Solid State Sciences最新文献

{"title":"Fe-doping effect on CoMoO4 for electrochemical oxygen evolution in neutral media","authors":"Li Yu,&nbsp;Qin Liang","doi":"10.1016/j.solidstatesciences.2025.108078","DOIUrl":"10.1016/j.solidstatesciences.2025.108078","url":null,"abstract":"<div><div>As an economically viable and environmentally benign electrocatalyst, CoMoO₄ has emerged as a promising alternative to noble metal-based water oxidation catalysts in recent years. However, the oxygen evolution reaction (OER) under neutral condition presents a significantly greater challenge compared to reactions occurring in acidic or alkaline electrolytes. Therefore, to further enhance the OER activity of CoMoO₄ under neutral conditions, we adopted an Fe-doping strategy. By precisely controlling the synthesis time, we successfully developed a series of Fe-CoMoO-X samples with varying morphologies (where X represents the synthesis time, ranging from 10 to 16 h) for electrocatalytic OER. By integrating multiple material characterization techniques with advanced electrochemical evaluation methods, we confirmed that the synthesis time profoundly influences the morphology of the Fe-CoMoO-X samples, which directly correlates with their catalytic performance for oxygen evolution. Moreover, all Fe-doped samples demonstrate markedly enhanced electrocatalytic activity compared to pristine CoMoO₄. Notably, the Fe-CoMoO-13 h sample exhibits the most superior oxygen evolution performance, achieving an overpotential of only 380 mV at a 10 mA cm⁻² (Tafel slope of 289 mV dec⁻¹), substantially lower than that of pure CoMoO₄ (400 mV at 10 mA cm⁻²; Tafel slope of 403 mV dec⁻¹). This improvement can be attributed to the partial substitution of Co atoms with Fe atoms in the doped CoMoO₄ structure, which modulates its electronic properties and enhances charge transfer kinetics.</div></div>","PeriodicalId":432,"journal":{"name":"Solid State Sciences","volume":"169 ","pages":"Article 108078"},"PeriodicalIF":3.3,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploration and control of short-chain spacer cations propylammonium and propanediammonium for tuning structure property performance relationships in 2D perovskites","authors":"Aboubacar Traore ,&nbsp;Mohammadreza Hosseini ,&nbsp;Atena Pakzadiyan ,&nbsp;Xing Li ,&nbsp;Jiahong Pan ,&nbsp;Xuepeng Liu ,&nbsp;Songyuan Dai ,&nbsp;Molang Cai","doi":"10.1016/j.solidstatesciences.2025.108073","DOIUrl":"10.1016/j.solidstatesciences.2025.108073","url":null,"abstract":"<div><div>The structural diversity of 2D perovskites, resulting from the integration of various spacer cations, remains insufficiently explored, necessitating a thorough investigation into the mechanisms that govern their structural, optoelectronic, surface moisture resistance, mechanical stability, and photovoltaic performance. This study examines the use of short-chain spacer cations to adjust and control these properties. We analyse the impact of Propylammonium (PA⁺) and Propanediammonium (PDA²⁺) on the structure-property-performance relationships in Ruddlesden-Popper-type (PA₂(MA)Pb₂I₇) and Dion-Jacobson-type (PDA(MA)Pb₂I₇) perovskites, based on first-principles calculations. Our results demonstrate that incorporating PDA²⁺ yields shorter intercalation distances, a higher volumetric density (3.87 g/cm³), and a more compact structure, resulting in monoclinic symmetry and a narrower band gap (1.8 eV). This configuration enhances absorption and charge carrier transport by lowering the excitation binding energy, resulting in a more pronounced Rashba effect due to reduced symmetry. This, in turn, enhances carrier lifetime through indirect transitions. These factors contribute to a higher short-circuit current density (19.64 mA/cm²) and better SLME efficiency (27 %) compared to that of PA₂(MA)Pb₂I₇ (11.16 mA/cm², 19 %), which adopts a less compact orthorhombic structure (3.17 g/cm³) with a wider band gap (2.17 eV). Mechanical analysis reveals that both perovskites are ductile, with the PDA²⁺-based perovskite showing greater rigidity and fracture resistance. In contrast, the PA⁺ cation induces higher ductility, as well as a higher water migration barrier and better resistance to water absorption compared to the PDA²⁺ cation. These results highlight the crucial importance of spacer cation selection and crystalline symmetry in determining the properties of 2D perovskites.</div></div>","PeriodicalId":432,"journal":{"name":"Solid State Sciences","volume":"169 ","pages":"Article 108073"},"PeriodicalIF":3.3,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"P-type thermoelectric properties of TiNi1–x–yCoySn half-Heusler alloy with reduced interstitial Ni atoms","authors":"Kosuke Yamazaki ,&nbsp;Sopheap Sam ,&nbsp;Hiroshi Nakatsugawa","doi":"10.1016/j.solidstatesciences.2025.108060","DOIUrl":"10.1016/j.solidstatesciences.2025.108060","url":null,"abstract":"<div><div>TiNiSn is an N-type thermoelectric material with low toxicity. The electrical conduction of TiNiSn can be tuned from N-type to P-type by substituting Co atoms at Ni sites. However, the <em>ZT</em> value is lower than that of the N-type TiNiSn, primarily due to its higher electrical resistivity. To decrease the electrical resistivity, it is necessary to increase the carrier density or mobility; however, the absolute value of the Seebeck coefficient decreases, which has a trade-off relationship with the electrical resistivity. To solve this problem, we prepared P-type thermoelectric materials TiNi_{1<strong>–</strong><em>x</em><strong>–</strong><em>y</em>}Co_<em>y</em>Sn (0 ≤ <em>x</em> ≤ 0.1, 0.01 ≤ <em>y</em> ≤ 0.05) with reduced interstitial Ni atoms by arc melting and heat treatment process. As a result, we successfully improved the electrical conductivity while maintaining the Seebeck coefficient. The hole carrier density increases as the number of interstitial Ni atoms decreases, and the electrical resistivity decreases by 78 % from 2.78 × 10⁻² Ωcm (for <em>x</em> = 0, <em>y</em> = 0.05) to 6.02 × 10⁻³ Ωcm (for <em>x</em> = 0.03, <em>y</em> = 0.05) at 300 K. The <em>ZT</em> value increases by a factor of 1.5 (<em>ZT</em>_max = 0.18 at 700 K) for TiNi_0.92Co_0.05Sn compared to TiNi_0.95Co_0.05Sn, indicating that the reduction of interstitial Ni atoms is effective in improving the thermoelectric properties of the P-type half-Heusler alloy TiNiSn. The peak <em>ZT</em> of 0.18 remains below the level required for practical implementation; however, this can be further improved by decreasing the lattice thermal conductivity.</div></div>","PeriodicalId":432,"journal":{"name":"Solid State Sciences","volume":"169 ","pages":"Article 108060"},"PeriodicalIF":3.3,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New layered quaternary Zintl pnictide oxides Ba2Zn2Pn2O (Pn = Sb, Bi): Discovery, crystal structures, band engineering, and transport properties","authors":"Mohd Ishtiyak ,&nbsp;Hussien H. Osman ,&nbsp;Spencer R. Watts ,&nbsp;Md Rashed Alam ,&nbsp;S.M. Gayomi K. Samarakoon ,&nbsp;Thimira Kandabadage ,&nbsp;Bhushan Thipe ,&nbsp;Samuel Gallego-Parra ,&nbsp;Xiaojian Bai ,&nbsp;David P. Young ,&nbsp;Sviatoslav Baranets","doi":"10.1016/j.solidstatesciences.2025.108059","DOIUrl":"10.1016/j.solidstatesciences.2025.108059","url":null,"abstract":"<div><div>Three new heteroanionic oxypnictides, Ba₂Zn₂Sb₂O, Ba₂Zn₂Bi₂O, and the solid solution Ba₂Zn₂Sb_{2−<em>x</em>}Bi_<em>x</em>O (<em>x</em> ≈ 1.1–1.6), have been synthesized and structurally characterized. They are isostructural with their Mn-bearing analog, adopting the Ba₂Mn₂Sb₂O-type structure (space group <em>P</em>6₃/<em>mmc</em>, No. 194), and feature a double-layered 2D <span><math><mrow><mtable><mtr><mtd><mn>2</mn></mtd></mtr><mtr><mtd><mi>∞</mi></mtd></mtr></mtable></mrow></math></span> [Zn₂<em>Pn</em>₂O]^2- substructure (<em>Pn</em> = Sb, Bi, Sb/Bi) composed of corner-sharing, distorted tetrahedral Zn<em>Pn</em>₃O units. Electronic structure calculations reveal a systematic progression from semiconducting Ba₂Zn₂Sb₂O to metallic Ba₂Zn₂Bi₂O as Bi content increases. These trends are corroborated by transport property measurements, with Ba₂Zn₂Sb_0.9(1)Bi_1.1O exhibiting relatively low electrical resistivity, high Hall mobilities of ∼160 cm²/V·s, and large Seebeck coefficients from 69 to 132 μV K⁻¹ over the 300–600 K temperature range. Comparison with structurally related Zintl pnictides, such as SrIn₂As₂ and PrZn₃As₃ phases, situates Ba₂Zn₂<em>Pn</em>₂O (<em>Pn</em> = Sb, Bi) within a broader family of heteroanionic oxypnictide Zintl compounds, highlighting their structural flexibility and amenability to band engineering. Electronic structure and bonding considerations point to tunable semiconducting behavior and underscore the relevance of these materials for thermoelectric and topological applications.</div></div>","PeriodicalId":432,"journal":{"name":"Solid State Sciences","volume":"169 ","pages":"Article 108059"},"PeriodicalIF":3.3,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hierarchical organic-inorganic PANI/CuWO4 nanocomposite as high-performance and robust electrode for advanced supercapacitors","authors":"Ali B.M. Ali ,&nbsp;Syed Waheedullah Ghori ,&nbsp;M.A. Diab ,&nbsp;Rekha M M ,&nbsp;Subhashree Ray ,&nbsp;Kattela Chennakesavulu ,&nbsp;Renu Sharma ,&nbsp;Asilbek Abdullaev ,&nbsp;Mutabar Latipova ,&nbsp;Ruslanbek Siddikov ,&nbsp;Aseel Smerat","doi":"10.1016/j.solidstatesciences.2025.108070","DOIUrl":"10.1016/j.solidstatesciences.2025.108070","url":null,"abstract":"<div><div>The development of advanced supercapacitor electrode materials with high energy density and robust cycling stability remains a critical challenge for next-generation energy storage systems. Hybrid nanocomposites combining conductive polymers and transition metal oxides offer a promising route to overcome these limitations by integrating the merits of both components. In this study, a polyaniline (PANI)/CuWO₄ nanocomposite was synthesized through in situ oxidative polymerization of aniline in the presence of CuWO₄ nanoparticles, and the resulting material was directly deposited onto a nickel sheet (NS) substrate using a drop-casting method without the addition of binders. The structural and morphological properties of the composite were characterized using FESEM, TEM, XRD, XPS, and EDS analyses, which collectively revealed a hierarchical flower-like nanosheet architecture for the PANI/CuWO₄ nanocomposite. Electrochemical performance was evaluated in a two-electrode configuration with 6 M KOH electrolyte via cyclic voltammetry and galvanostatic charge–discharge (GCD) measurements. The PANI/CuWO₄/NS electrode exhibited an outstanding specific capacitance of 323 F g⁻¹ at 0.5 A g⁻¹, a high energy density of 16.16 Wh kg⁻¹, and excellent capacitance retention of 90.75 % after extensive cycling. The hierarchical porous architecture, confirmed by BET and TEM, facilitated rapid ion/electron transport and buffered mechanical stress during repeated charge/discharge cycles. These results highlight the PANI/CuWO₄/NS nanocomposite as a highly efficient and durable electrode material for advanced supercapacitor applications.</div></div>","PeriodicalId":432,"journal":{"name":"Solid State Sciences","volume":"169 ","pages":"Article 108070"},"PeriodicalIF":3.3,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pore-partitioned bimetallic metal-organic frameworks for efficient photocatalytic activation of peroxymonosulfate","authors":"Wenxu Ma,&nbsp;Zhiyong Liu,&nbsp;Yunqiong Yang","doi":"10.1016/j.solidstatesciences.2025.108056","DOIUrl":"10.1016/j.solidstatesciences.2025.108056","url":null,"abstract":"<div><div>Metal-organic frameworks (MOFs) have been widely explored in photocatalytic peroxymonosulfate-based (PMS) advanced oxidation processes (AOPs) due to their highly tunable and porosity structures. In this work, three pore-partitioned MOF materials, namely [Fe₃M₂O(BDC)₃(trz)₃Cl₂(H₂O)₄]·solvent (Fe₃+M₂, M = Mg, Fe, or Zn, BDC = terephthalic acid, trz = 1,2,4-triazole), were successfully synthesized by embedding binuclear units [M₂(trz)₃] (M = Mg, Fe, or Zn) into a MIL-88B structure (Fe₃). It is demonstrated that binuclear units can introduce a large number of potential open metal sites, regulate framework stability, and optimize adsorption capacity, thereby enhancing the photocatalytic property of MOFs. Fe₃+Mg₂/PMS system showed a RhB removal efficiency of 97.5 % in 10 min under visible light irradiation, giving a degradation rate constant of 0.28 min⁻¹. In addition, the photocatalytic mechanism was also systematically investigated. This study provides a new clue for developing highly efficient and stable MOF-based catalysts for AOPs.</div></div>","PeriodicalId":432,"journal":{"name":"Solid State Sciences","volume":"169 ","pages":"Article 108056"},"PeriodicalIF":3.3,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145009888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Features of antibiotic and bacteria decomposition under visible light by photocatalysts based on some β-pyrochlores in system CsMxW2-xO6 (x= 0–0.5, M = Sn, Mo, V)","authors":"Alexander S. Ganov,&nbsp;Diana G. Fukina,&nbsp;Andrey Yu Shishkin,&nbsp;Alina A. Parchacheva,&nbsp;Andrey V. Koryagin,&nbsp;Kseniya A. Shishkina,&nbsp;Ilya S. Belyansky,&nbsp;Vasily F. Smirnov,&nbsp;Evgeny V. Suleimanov","doi":"10.1016/j.solidstatesciences.2025.108052","DOIUrl":"10.1016/j.solidstatesciences.2025.108052","url":null,"abstract":"<div><div>The powders of CsW₂O₆, CsM_0.25W_1.75O₆ (M = Sn, V) and CsMo_xW_2-xO₆ (x = 0.1, 0.25, 0.5) with β-pyrochlore structure were synthesized by sol-gel method. The phase and elemental composition individuality has been confirmed by X-ray diffraction analysis and X-ray microanalysis. The particle size distribution by volume of prepared powder has shown that average particle size is about 400–500 nm, whereas the specific surface area changes in the range 7–36 m²/g depended on composition. The mechanism of photocatalytic decomposition using CsW₂O₆, CsM_0.25W_1.75O₆ (M = Sn, V) and CsMo_xW_2-xO₆ (x = 0.1, 0.25, 0.5) has been investigated, the high influence the recombination process on the conversion degree was detected. The photocatalytic decomposition of levofloxacin and bacteria was studied under visible light irradiation.</div></div>","PeriodicalId":432,"journal":{"name":"Solid State Sciences","volume":"168 ","pages":"Article 108052"},"PeriodicalIF":3.3,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144889435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lead-free X2MgGeI6 (X = Rb, Cs) double perovskites for multi-functional energy applications: A DFT and SCAPS-1D Perspective","authors":"Asif Nawaz Khan ,&nbsp;Naimat Ullah Khan ,&nbsp;Muhammad Kaleem ,&nbsp;Muhammad Tanzeel ,&nbsp;Amna Nasir ,&nbsp;Asif Hosen ,&nbsp;Ali Akremi ,&nbsp;Imed Boukhris","doi":"10.1016/j.solidstatesciences.2025.108049","DOIUrl":"10.1016/j.solidstatesciences.2025.108049","url":null,"abstract":"<div><div>This research aims to explore cost-effective and eco-friendly stable lead-free double halide perovskites X₂MgGeI₆ (X = Rb, Cs) for renewable energy applications. All computations were performed using WIEN2k. The PBE-GGA was used to optimize crystal structure, and the TB-mBJ potential estimated electronic characteristics. The compound X₂MgGeI₆ (X = Rb, Cs) is tested for power conversion efficiency using SCAPS-1D. Thermodynamics and structural stability were assessed using molecular dynamics, negative formation energies, and tolerance factor calculations. Both Rb₂MgGeI₆ and Cs₂MgGeI₆ exhibit indirect semiconductor nature with energy band gaps of 1.5 and 1.495 eV. Due to their lower effective masses and exciton binding energies, and promising optical characteristics, the understudy compounds may be used in solar cells and optoelectronic devices. Photocatalytic properties make the investigated materials promising hydrogen splitting candidates for solar-powered water splitting. Moreover, X₂MgGeI₆ (X = Rb, Cs) has significant solar energy conversion potential, achieving (30–32)% power conversion efficiency (PCE).</div></div>","PeriodicalId":432,"journal":{"name":"Solid State Sciences","volume":"168 ","pages":"Article 108049"},"PeriodicalIF":3.3,"publicationDate":"2025-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144878299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase equilibria and properties of complex oxides in the ½ Eu2O3 – ½ Fe2O3 – CoO system","authors":"N.E. Volkova,&nbsp;T.V. Aksenova,&nbsp;L.Ya. Gavrilova,&nbsp;V.A. Cherepanov","doi":"10.1016/j.solidstatesciences.2025.108048","DOIUrl":"10.1016/j.solidstatesciences.2025.108048","url":null,"abstract":"<div><div>Phase equilibria in the ½ Eu₂O₃ – ½ Fe₂O₃ – CoO system are studied at 1100 °C in air. A continuous series of EuFe_1-<em>x</em>Co_<em>x</em>O_3-δ solid solutions between europium ferrite and europium cobaltite with an orthorhombically distorted perovskite structure (SG <em>Pbnm</em>) has been confirmed. The unit cell parameters and unit cell volume of EuFe_1-<em>x</em>Co_<em>x</em>O_3-δ solid solutions obey Vegard's law. The homogeneity ranges of solid solutions in quasi-binary ½ Fe₂O₃ – CoO constituent subsystems at 1100 °C in air, taken from various works, are analyzed, and a phase diagram for the ½ Eu₂O₃ – ½ Fe₂O₃ – CoO system, consisting of 4 two-phase and 3 three-phase fields is constructed. The oxygen content in EuFe_1-<em>x</em>Co_<em>x</em>O_3-δ solid solutions is determined by the hydrogen reduction and iodometric titration methods. Oxygen losses with increasing temperature are small, maximum oxygen deficiency δ at 1000<em>°</em>C does not exceed 0.05. Linear thermal expansion of EuFe_1-<em>x</em>Co_<em>x</em>O_3-δ ceramics was measured by dilatometry. The nonlinear behavior of the dilatometric curves is discussed in terms of a possible change in the spin state of Co³⁺ ions. Electrical conductivity, which is low at room temperature and does not differ for all the samples studied, increases significantly with increasing temperature and Co content.</div></div>","PeriodicalId":432,"journal":{"name":"Solid State Sciences","volume":"168 ","pages":"Article 108048"},"PeriodicalIF":3.3,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144852811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure, thermal properties and phase transition in RbCdHfF7: experiments and lattice dynamics calculations","authors":"Evgeniy V. Bogdanov ,&nbsp;Maxim S. Molokeev ,&nbsp;Mikhail V. Gorev ,&nbsp;Andrey V. Kartashev ,&nbsp;Maxim S. Pavlovskiy ,&nbsp;E.I. Pogoreltsev ,&nbsp;Natalia M. Laptash ,&nbsp;Igor N. Flerov","doi":"10.1016/j.solidstatesciences.2025.108042","DOIUrl":"10.1016/j.solidstatesciences.2025.108042","url":null,"abstract":"<div><div>A mixed-cation fluoride RbCdHfF₇ was synthesized. The room temperature structure was determined as orthorhombic (<em>Cmcm</em>, <em>Z</em> = 4). Comprehensive studies of thermal properties and permittivity revealed a phase transition of a non-ferroelectric nature at <em>T</em>₀ = 207 K.</div><div>Calculations using the density functional theory, as well as the behavior of the order parameter Ω(<em>T</em>), indicate a doubling of the unit cell volume in the low-temperature phase, which is associated with an unstable mode at the <em>S</em> boundary point of the Brillouin zone. The monoclinic symmetry (<em>P</em>2₁/<em>c</em>, <em>Z</em> = 4) was chosen for phase below <em>T</em>₀. Very high sensitivity to hydrostatic pressure and low entropy of structural transformation were found and discussed.</div></div>","PeriodicalId":432,"journal":{"name":"Solid State Sciences","volume":"168 ","pages":"Article 108042"},"PeriodicalIF":3.3,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144865220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}