Artículos SCI

To understand the influence of precursors on the physicochemical and photocatalytic properties of silver bromide, AgBr photocatalysts were synthesized by a simple precipitation method using different silver (AgNO₃, Ag(NH₃)₂⁺) and bromine (KBr, CTAB) sources. Samples were characterized and tested against rhodamine B (RhB), methyl orange (MO), and paracetamol (PCT). Depending on the precursor used, differences in morphology, particle size and surface composition were observed, obtaining single AgBr, Ag/AgBr, and AgBr/CTAB materials. From these materials, single AgBr and Ag/AgBr photocatalysts obtained the highest conversion percentages for RhB and PCT, while the AgBr/CTAB photocatalysts have a restricted photoactivity with the evaluated substrates, since the CTAB molecules have a strong interaction with MO and compete with the substrates to react with the reactive oxygen species (ROS) generated by the photocatalysts. Recycling tests suggest that all samples suffer photocorrosion, decreasing their photocatalytic capacity and forming depots of metallic silver on their surfaces. Overall, these findings demonstrate that the selection of silver and bromine sources during AgBr synthesis strongly determines the morphological, surface, and photocatalytic properties of the semiconductor, providing insights into the rational design of silver halide-based photocatalysts for environmental remediation.

Silver nanoparticles stabilized by amino acid-derived N-heterocyclic carbenes, denoted as Ag(NHCR)-NPs (R = H, 3a; Me, 3b; iPr, 3c; and iBu, 3d), were synthesized by reducing the parent complexes Na3[Ag(NHCR)2] (2a-d) with NaBH4 under appropriate reaction conditions. The stability of the aqueous AgNP solutions was found to depend strongly on the presence of the NHC ligand, the solution concentration, and the nature of the R substituent. In particular, the stability of the nanoparticles decreases as the steric bulk of R increases. Among the series, 3a (R = H) exhibits remarkable stability in water and can be isolated by ultracentrifugation and lyophilization. Notably, solid Ag(NHCH)-NPs (3a) can be redissolved in water to regenerate a stable AgNP solution. The Ag(NHCR)-NPs were characterized by infrared (IR) and ultraviolet-visible (UV-Vis) spectroscopies, polarimetry, dynamic light scattering (DLS), and transmission electron microscopy (TEM). 3a behaves as an active and versatile nanocatalyst in water, efficiently promoting both the model reduction of 4-nitrophenol to 4-aminophenol and the catalytic hydrolysis of NaBH4 to generate H2 under basic conditions. From a theoretical perspective, the nucleation and growth of the Ag(NHCR)-NPs were modelled using density functional theory (DFT) at the PBE-D3/def2-TZVP level, considering systems of the type [Agn(NHCR)]2- (with R = H, Me and iPr and n = 2, 3, 4, 20, 30). The Quantum Theory of Atoms in Molecules (QTAIM) was employed to analyze the bonding characteristics within the nanoparticles, with particular attention to the Ag-Ag and Ag-C(carbene) interactions. It is noteworthy that the bond dissociation energy (BDE) of the Ag-C(carbene) bond decreases with increasing steric bulk of R, consistent with the experimental observations. Based on experimental data, the Ag : NHC ratio is approximately 30 : 1 and the calculated IR spectrum of [Ag30(NHCH)]2- model (corresponding to 3a) provides a satisfactory match with the experimental spectrum.

This work offers a systematic study of the electrical conductivity in dense 8 mol% yttria-stabilized zirconia (8YSZ) during non-isothermal and isothermal AC-flash conditions under a fixed applied voltage. Conductivity data were interpreted using a two-barrier ionic transport model which is able to capture the non-Arrhenius behavior commonly found for 8YSZ. The analysis of the conductivity evolution indicates that AC-flash in 8YSZ may be understood as a time-dependent breakdown process where the field exposure duration plays a critical role, driven by similar charge transport mechanisms regardless of the employed methodology. A characteristic sequence of electrical resistance degradation, previously described for 8YSZ subjected to DC fields, is also observed under AC fields, suggesting the involvement of partial discharge mechanisms and charge accumulation effects in the formation of conductive paths eventually leading to the flash event. These findings highlight the limitations of time-independent conductivity models to fully describe AC-flash processes in 8YSZ ceramics.

Objective: To develop an innovative hydraulic bioceramic (HB) formulation by incorporating zinc-functionalized mesoporous bioactive glass (MBG-Zn) into a commercial calcium silicate-based cement (ProRoot MTA White), aiming to enhance bioactivity, accelerate setting kinetics, and improve clinical performance. Methods: A modified cement (MTA-MBG-Zn) was processed by blending MTA with 15 wt% MBG-7.5Zn. The physicochemical properties, including crystalline phases, microstructure and textural characteristics, were analyzed. Functional performance was evaluated through setting time measurements, in vitro bioactivity in simulated body fluid (SBF), and biocompatibility using human dental pulp stem cells (hDPSCs). Results: MTA-MBG-Zn exhibited increased surface area and porosity, resulting in faster bioactive response and reduced final setting time compared to unmodified MTA. Enhanced hydroxyapatite formation and elevated silicon ion release were observed, alongside reduced release of potentially toxic bismuth and aluminum ions. Both materials demonstrated excellent biocompatibility, with MTA-MBG-Zn showing slightly higher cell viability and alkaline phosphatase activity. Significance: The integration of MBG-Zn into calcium silicate-based cement significantly improves its physicochemical and biological performance. These findings support the potential of MTA-MBG-Zn as an advanced material for regenerative endodontics, offering enhanced biomineralization, sealing ability, and a more favorable ion release profile.

The biomechanical behavior and corrosion phenomena of porous metallic implants can compromise their clinical success. This work proposes modifying the surface of c.p. titanium scaffolds manufactured by 3D-printing (Direct Ink Writing), depositing a thin film of a beta-Ti alloy (Ti-35Nb-7Zr-5Ta) using the High-Power Impulse Magnetron Sputtering (HiPIMS) technique. The versatility of this technique has enabled the fabrication of conformal coatings with uniform thickness, excellent adhesion, a nanorough surface, and a homogeneous columnar distribution. Regarding the biofunctional behavior of the coatings, contact angle measurements and a comprehensive electrochemical study (including impedance spectroscopy, open-circuit potential, and anodic polarization) were performed in artificial saliva. The results are discussed in terms of 1) the potential of the HiPIMS technique; and 2) the role of the coating (effect on stress shielding, improved corrosion resistance, and fatigue life potential). Electrochemical measurements demonstrate the effectiveness of the coating in improving corrosion resistance. In particular, the corrosion current density decreased from 1.62 +/- 0.06 mu A/cm2 for uncoated scaffolds to 0.31 +/- 0.01 mu A/cm2 after coating. At the same time, the polarization resistance increased nearly fivefold (from 0.84 x 105 to 3.72 x 105 Omega & sdot;cm2), confirming the protective effect of the TNZT film. The scaffold porosity favors bone ingrowth, while the reduced Young's modulus of the HiPIMS-deposited TNZT coating minimizes bone resorption. Moreover, its higher nanohardness suggests a potential increase in fatigue resistance. Finally, the synergistic combination of DIW-engineered porosity and a compact HiPIMS-deposited TNZT film will successfully alleviate stress shielding while enhancing corrosion resistance and biofunctional compatibility.

Combination of self-propagating high-temperature synthesis (SHS) from Ti + B powder mixture followed by spark plasma sintering (SPS) is introduced for the fabrication of titanium diboride. Oxide impurities, including zirconium oxide and titanium oxide, are identified in the synthesized powders: the first one coming from the milling process after SHS to minimize agglomeration and the second one is a common oxide fine layer on particle surface. Both oxide phases are reduced during SPS treatment. Results confirm that increasing the SPS temperature enhances the reduction of ZrO2, facilitating the incorporation of Zr cations into the lattice through substitution at Ti sites, thus allowing the formation of this solid solution diboride: Ti1-xZrxB2. The key finding is that the presence of a small amount of Zr cation, with higher atomic radius in TiB2 crystal structure results in crystal distortion and it creates significant solid solution hardening effect as well as an improved wear response.

Ex vivo human tooth culture models preserve the native dentine-pulp complex and offer a translational platform to study pulp-capping biomaterials. This systematic review aimed to synthesize the evidence on histological pulp tissue responses to calcium silicate-based cement (CSCs) used for direct pulp capping in human tooth culture models. The review followed PRISMA 2020 guidance. Eligible studies were ex vivo whole human tooth culture models with direct pulp exposure treated with commercial or experimental CSCs and reporting histological outcomes. Risk of bias was assessed using the QUIN tool. Thirteen studies were included. Most used immature human third molars (from 15- to 19-year-old patients) and culture periods up to 28 days, with a minority extending observation to 45-90 days. Across hydraulic CSCs, Biodentine was the most frequently evaluated material, followed by ProRoot MTA and several experimental hydraulic and resin-modified formulations. Overall, hydraulic CSCs were consistently associated with biocompatible pulp responses and a pro-mineralization pattern characterized by periexposure mineralized foci/osteodentin-like tissue; where assessed, immunohistochemistry supported odontoblast-like differentiation. In contrast, the resin-modified CSC TheraCal LC and other experimental resin-modified CSCs showed more heterogeneous findings, with reports of absent, delayed, or less prominent mineralization compared with reference hydraulic CSCs. In intact human tooth culture models, hydraulic CSCs show reproducible biocompatibility and early mineralization features consistent with reparative dentinogenesis, whereas resin-modified CSCs demonstrate more variable histological performance.

We demonstrate robust exciton-polariton formation in planar metallic optical cavities incorporating porphyrin-based Metal-Organic Framework (MOF) nanoparticles. Our fabrication strategy employs highly monodisperse fluorinated MOF nanoparticle monolayers, sequentially coated with transparent silicon dioxide nanoparticles, enabling precise control over film thickness while preserving MOF pore accessibility. This architecture ensures well-defined excitonic transitions and facilitates alignment of the MOF exciton transition dipole moments with the cavity electric field, thereby maximizing coupling strength. Experimental polariton absorption energy dispersion relations unequivocally reveal light-matter hybridization through clear anticrossing of the upper and lower polaritonic branches, yielding Rabi splittings as large as 440 meV, placing the system at the threshold of the ultra-strong light-matter coupling regime. Critically, these MOF nanoparticle optical cavities exhibit unprecedented, precise, and reversible tuning of the polariton absorption splitting upon exposure to gradual vapor pressure changes. This tunability stems both from the adsorption/desorption properties of the MOF nanoparticle mesostructured pore network and the porphyrin ligand solvatochromic character. Our work constitutes an unparalleled demonstration of chemical environment-controlled exciton-polariton fine tuning, opening new avenues for responsive polaritonic materials in sensing, catalysis, and photochemistry.

Sub-stoichiometric titanium carbide ceramics were synthesized via a hybrid route combining self-propagating high-temperature synthesis (SHS) and spark plasma sintering (SPS). TiC1-x powders were produced through a single, rapid SHS step by the direct reaction of titanium and graphite, followed by attrition milling to achieve an average particle size of 3-5 mu m. Particular attention was devoted to analyzing sub-stoichiometry variations associated with carbon vacancy formation during both SHS and SPS processes. SPS treatments at temperatures up to 1800 degrees C promoted sub-stoichiometric deviations reaching compositions as low as TiC0.74, which remained nearly stable even under more extreme SPS conditions. Additionally, a minor and unexpected precipitation of a disordered graphite phase was detected. The resulting sub-stoichiometric titanium carbide ceramics exhibited high Vickers hardness values, reaching up to 27 GPa. Microstructural analysis revealed plastic deformation, attributed to dislocation interactions with graphite precipitates. The dislocation dynamics were found to be governed by cationic diffusion mechanisms.

Thermochromic VO2 crystalline domains have been formed in amorphous nanocolumnar VOx films by means of a low-temperature oxidation process. The oxidation of an amorphous film with [O]/[V] below 1.9 favors the formation of VO2, V3O7, and V2O5 crystalline domains in the material for temperatures as low as 260 degrees C, while values above 1.9 lead to the sole formation of the V2O5 phase. It is found that the absorption of oxygen also causes a relevant film volume expansion that makes pores shrink. Under some specific conditions, low-temperature oxidation causes the near disappearance of the amorphous regions, clearly improving the overall transparency and optimizing the optical and electrical modulation capabilities associated with the presence of crystalline VO2 domains. The best thermochromic performance was found when the original stoichiometry was [O]/[V] = 1.5 and the oxidation temperature was 280 degrees C. These conditions yield a relatively transparent coating in the visible range that presents an optical modulation in the near-infrared range of nearly 50% and a drop of electrical resistivity of more than two orders of magnitude, with a transition temperature of 50.3 degrees C. A tentative model based on the volume expansion experienced by the film upon oxidation is proposed, which links the structural/chemical features of the material and the formation of the crystalline domains at such relatively low temperatures.

Poly(lactic acid) (PLA) is a bio-based polymer with high potential; however, its inherent brittleness restricts its practical applications. This work evaluates ethylene brassylate (EB), a macrocyclic diester of natural origin, as a plasticizer for PLA at 5–20 wt%. Thermal analysis confirmed a plasticizing effect, with the glass transition temperature decreasing from 59.9 °C in neat PLA to 38.0 °C in PLA-20 EB. Mechanical tests showed that 20 wt% EB increased elongation at break from 10 % (neat PLA) to over 460 % and improved impact resistance by ∼70 %. Furthermore, moisture resistance was preserved, and microscopy confirmed good miscibility with no phase separation. Under composting, degradation occurs more rapidly in proportion to EB content, reaching ∼90 % mass loss after four weeks. Migration tests revealed values below 40 mg kg⁻¹ for PLA-EB < 10 wt% EB, whereas PLA-15 EB reached the regulatory limit. EB is therefore an efficient bio-based plasticizer for PLA, offering enhanced ductility, toughness, and biodegradation, with promising applications in sustainable packaging, especially for refrigerated and cold-chain storage. © 2025 The Authors

Metal halide perovskite solar cells (MHPSCs) hold great promise due to their high efficiency and low fabrication costs, but their long-term stability under environmental conditions remains the main challenge. However, their long-term operational stability under environmental stress remains a critical limitation for commercialization. In this work, we explore a dual passivation strategy using ultrathin adamantane-based plasma polymer (ADA) films, deposited via remote plasma-assisted vacuum deposition (RPAVD), to enhance the environmental stability of MHPSCs. The ADA layers are introduced simultaneously at both the electron transport layer (ETL)/perovskite and perovskite/hole transport layer (HTL) interfaces, offering a conformal, transparent, and thermally stable coating compatible with delicate perovskite films. This approach enables interfacial defect passivation and acts as a protective barrier against moisture and UV-induced degradation. Devices incorporating ADA layers exhibit significantly improved stability under harsh conditions, retaining 80 % of their initial efficiency after 4000 min over extended exposure to humidity and continuous illumination. These results demonstrate the potential of multifunctional plasma-polymer coatings for the scalable and robust fabrication of perovskite solar cells with enhanced durability.

The pressing demand for sustainable alternatives to fossil fuels coupled with environmental risks associated with inappropriate sewage sludge (SS) disposal calls for innovative valorization strategies that transform waste into value-added products. This study introduces a novel approach by directly incorporating zeolite catalysts (HZSM-5 and USY) into the hydrothermal carbonization (HTC) of SS, followed by pyrolysis (Py) of the derived hydrochar (HC). Insights into derived HC are explored through comprehensive characterization, such as morphology, crystallinity, functionality, and thermal analysis. HZSM-5 significantly reduced the activation energy of HC from 27 to 5.5 kJ mol-1, while increasing the structural disorder (ID/IG0.73). The selective production of CO and H2 was achieved through temperature-dependent pyrolysis between 500 and 900 degrees C. HZSM-5 facilitated an increase in CO production to 54.18%, whereas USY boosted CO yield up to 35.6%. The optimal product distribution was achieved by strategically incorporating zeolite catalysts, allowing for precise control of N and O functionality and promoting selective syngas and chemical precursors yield. This innovative catalyst-mediated HTC-Py cascade offers unique control over pyrolytic products by introducing an efficient pathway for transforming problematic SS into green energy carriers, thus bridging the gap between environmental sustainability and feasible industrial utilization.

The substitution of silicon into SrAl2O4 is of interest for the development of new persistent luminescence phosphors with complementary excitation and emission wavelengths, especially in the form of transparent ceramics or glass-ceramics by the glass-crystallization approach. Application of this approach to the series Sr1-x/2Al2-xSixO4 (0 <= x <= 1) has previously produced two different solid solutions adopting either the three-dimensional stuffed tridymite structure of SrAl2O4 (0 <= x <= 0.5), or the two-dimensional hexacelsian structure of SrAl2Si2O8 (0.8 <= x <= 1.0), with a compositional gap between 0.5 < x < 0.8. Here, we synthesize a solid solution centered around SrAl2SiO6 (x = 0.66), which is accessible in the range 0.60 <= x <= 0.75 by glass crystallization. The crystal structure of SrAl2SiO6 features an aluminosilicate framework that is related topologically to SrAl2O4 (stuffed tridymite) and also, more distantly, to SrAl2Si2O8 (hexacelsian), representing a stepwise reduction in framework dimensionality across the series. SrAl2SiO6 exhibits an unusual pale blue-green persistent luminescence when doped with Eu2+/Dy3+, and can be produced as powders or transparent glass-ceramic disks. The pale afterglow color, transparency and scalability of these materials are complementary to the dominantly green persistent luminescence of SrAl2O4-based powders or single crystals.

Deploying reliable and sustainable large-scale energy storage is a significant challenge for the widespread adoption of renewable energy sources. Thermal energy storage solutions can provide scalable solutions for renewable power and industrial processes. The calcium looping-based energy storage system stands out for its high energy density, low cost, non-toxicity, and wide availability of limestone as a precursor material. The thermochemical energy storage cyclic process occurs through the calcination of calcium carbonate and its subsequent recovery through carbonation of calcium oxide. This work presents the development and tests of a novel entrained flow carbonator developed during the SOCRATCES EU project. The results show for the first time a successful CaO carbonation reaction in kW-scale equipment under energy storage conditions. The carbonation reaction occurs in an entrained flow reactor in few seconds at the temperature and pressure conditions required for the Calcium-looping-based energy storage system (700-800 degrees C). It demonstrates the feasibility of the entrained flow reactor concept for carbonation and its potential for MW-scale solar plants.

Lead halide perovskite nanocrystals (NCs) are promising materials for next-generation optoelectronic devices due to their exceptional optical properties. However, poor long-term stability remains a major challenge. In this study, formamidium lead bromide (FAPbBr3) NCs are embedded in a mesoporous silica matrix to enhance stability and explore exciton transport mechanisms. These NCs display a narrow photoluminescence (PL) linewidth of 25 meV at 7 K. The absence of surface ligands leads to reduced interparticle spacing, favoring non-radiative F & ouml;rster resonance energy transfer (FRET) as the dominant exciton transport mechanism. Using time-resolved and spectrally-resolved PL spectroscopy at cryogenic temperatures, it is observed significant spectral redistribution over time, indicating energy transfer from higher-energy to lower-energy NCs. To quantitatively interpret these dynamics, a theoretical model based on a 2D array of coupled NCs, incorporating F & ouml;rster's theory to simulate exciton diffusion is employed. This model successfully reproduces the experimentally observed PL decay behavior, confirming FRET-mediated exciton transport with an upper-limit efficiency close to 100% and a transfer rate of 105 ns-1. These findings offer key insights into energy transfer processes in ligand-free perovskite NC systems and underscore the potential of mesoporous silica matrices for improving stability and enabling control over excitonic interactions in perovskite-based optoelectronic applications.

Magnetic resonance imaging (MRI) is one of the most commonly used imaging techniques for diagnosis in clinics. Often, magnetically-active substances, called contrast agents (CAs), have to be used, which increase contrast by shortening the longitudinal (T1) (resulting in signal enhancement in T1-weighted images) and/or transverse (T2) (resulting in signal decay in T2-weighted images) relaxation times of the water protons present in biological tissues. A further strategy to improve diagnostic accuracy is recording both kinds of images (T1-weighted and T2-weighted) using dual T1-T2 CAs, which facilitates the exclusion of false positives. The traditional T1 or T2 contrast agents are not suitable for such a purpose. This paper deals with the development of double sodium lanthanide tungstate-based nanoparticles containing Gd3+ and Dy3+ cations, which are dispersible in physiological media, do not show appreciable in vitro (for human fibroblast cells) and in vivo (for C. elegans) toxicity and present appropriate relaxivity values for their use as a dual T1-T2 contrast agent for magnetic resonance imaging. In addition, they show an excellent X-ray attenuation capacity, thanks mainly to their tungsten content, which makes them also useful for X-ray computed tomography. Hence, the developed nanoparticles are ideal multimodal probes to be used as a dual T1-T2 contrast agent for magnetic resonance imaging and as a contrast agent for X-ray computed tomography.

The integration of biochars into photocatalytic systems to increase their efficiency in the degradation of different pollutants in water has gained attention in recent years. However, systematic studies on optimizing biochar properties for photocatalysis remain limited. This work explores the incorporation of biochar from olive pruning (BCO), produced via CO₂ pyrolysis at 800 °C, into WO₃/AgBr photocatalysts for Rhodamine B degradation used as a model pollutant. Characterization of BCO reveals a hydrophilic, porous material (487 m²/g surface area) rich in mineral content (notably CaCO₃). The study evaluates the effects of incorporation method (mechanical vs. in situ) and biochar content (1 and 10 wt. %) on photocatalytic performance. Comprehensive characterization of BCO and the resulting composites supports the observed activity trends. The findings highlight the potential of agricultural waste valorization for environmental remediation and offer insights into designing efficient biochar-based photocatalytic systems.

This paper explores the effectiveness of boron nitride nanosheets in preventing the premature failure of yttriastabilized tetragonal zirconia ceramics, particularly in humid environments. A simple, low-cost and scalable technique-shear exfoliation in a kitchen blender-was used to prepare BNNS, and pure zirconia and composites with 1, 2.5 and 5 vol. % BNNS were spark plasma sintered. Accelerated hydrothermal ageing experiments in autoclave revealed a remarkable improvement of low temperature degradation resistance in all the composites. Fracture toughness and slow crack growth of the composites with 1 and 2.5 vol. % BNNS were evaluated by bending tests performed in notched specimens. Although the composites presented fracture toughness values similar to those of the reference zirconia, an increase of similar to 18 % on crack-tip toughness was achieved. Similar Rcurves evaluated in air and in oil-impregnated 2.5 vol. % BNNS composites revealed a limitation of stress-assisted corrosion by water in zirconia, thanks to the BNNS incorporation.

Cardiovascular mortality remains a major health challenge. Cardiomyocyte (CM)-based tissue engineering (TE) offers promising alternatives for developing therapies via in vitro models. However, the immature phenotype of CM in engineered tissues hampers progress. Recent studies introduce conductive materials like graphene to enhance CM maturation, but conventional graphene synthesis suffers from complexity, toxicity, and low yield. Laser-induced graphene (LIG) provides a sustainable, cost-effective, eco-friendly solution with efficient conductivity and biocompatibility. A LIG-based substrate is bioengineered in this study, hypothesizing that its conductive, anisotropic properties promote CM maturation and mimic the native cardiac niche. LIG is fabricated using a CO2 laser with Parylene-C as a precursor. Stem cells (SCs) and SC-derived embryoid bodies (EBs) are cultured on LIG substrates, and their viability, metabolic activity, morphology, and protein expression are evaluated through immunofluorescence and electron microscopy. Both SCs and EBs maintain viability and activity throughout the culture. Moreover, EB-derived CM exhibit spontaneous contraction and express cardiac-specific proteins, confirming functional differentiation on LIG matrices. This first report demonstrates that LIG substrates support SC culture and differentiation, highlighting their potential in developing refined in vitro cardiac models and advancing regenerative therapeutic strategies. The findings support LIG as a transformative advancement in TE.

Lead-free piezoelectric ceramics (Ba1-xCax) (Ti1-yHfy)O-3 with stoichiometries close to the morphotropic phase boundary (MPB) were synthesized by high-energy ball milling. The influence of Hf and Ca contents and the sintering method (conventional and hot-press) on the piezoelectric, dielectric, and ferroelectric response was investigated. It was confirmed that the different phases stabilized at room temperature and the structural distortion are strongly dependent on the stoichiometry. The coexistence of tetragonal, orthorhombic and rhombohedral phases was observed in samples with the lowest Ca and Hf contents. These samples, which are in the MPB region, also showed the greatest structural distortion, resulting in higher values of d(33). Samples with lower Hf content exhibited a higher coercive field, remnant polarization, and temperature in the ferroelectric to paraelectric transition. Despite the high sintering temperature leading to high densification, grain growth during sintering was limited because of the use of mechanochemically synthesized powders. Although Ba0.85Ca0.15Hf0.10Ti0.90O3 stoichiometry has been reported in the literature as the best for piezoelectric properties, in this work, BCHT solid solution with the lowest dopant content studied (Ba0.90Ca0.10Hf0.05Ti0.95O3) showed the best combination of functional properties. Ceramics of this composition with grain size <2 mu m exhibited a d(33) > 250 pC/N, with almost no relaxation after 24 h, and the highest permittivity. In the field of piezoelectric materials, there is considerable interest in reducing grain size while maintaining high piezoelectric performance, as this can lead to improvements in mechanical properties.