Article
Chemistry, Physical
Gabriela Souca, Roxana Dudric, Ruxandra Cotop, Karsten Kuepper, Coriolan Tiusan, Romulus Tetean
Summary: The electronic structure, magnetic properties, and magnetocaloric effect of GdCo2-xNix alloys were investigated. The experiments and calculations confirmed the antiferromagnetic ground state, coupling between Gd and transition metals, and reduction of Co magnetic moments when substituting Ni. The presence of a second order magnetic phase transition was also observed.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
Anitha Anand, M. Manjuladevi, R. K. Veena, V. S. Veena, Yuri S. Koshkid'ko, S. Sagar
Summary: The study investigates the effect of Ti doping on structural, magnetic, and magnetocaloric properties of Nd-based manganites, finding that N-0.15 exhibits increased Working Temperature Span and decreased magnetic hysteresis loss, making it a potential candidate for low-temperature magnetic refrigeration.
MATERIALS RESEARCH BULLETIN
(2022)
Article
Polymer Science
G. Kadim, R. Masrour
Summary: In this work, the structural, electronic, magneto-optic, magnetocaloric and thermoelectric properties of Mn-doped PbS were investigated using first-principles density functional calculations and Monte Carlo simulation. The results showed that Mn doping slightly decreased the band gap of PbS and Pb0.5Mn0.5S exhibited antiferromagnetic behavior. The optical and thermoelectric properties were also analyzed in detail.
JOURNAL OF INORGANIC AND ORGANOMETALLIC POLYMERS AND MATERIALS
(2023)
Article
Chemistry, Physical
Sever Mican, Roxana-Alina One, Razvan-Claudiu Pop, Coriolan Viorel Tiusan, Romulus Tetean
Summary: The structural, magnetic, and magnetocaloric properties of PrCo3-xCux intermetallic compounds were studied. The experiments showed an anisotropic expansion of the unit cell along the c-axis with increasing Cu concentration, a decrease in Co atomic moments, and an enhancement of magnetocrystalline anisotropy. The magnetic entropy change decreased with increasing Cu concentration.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
C. Henchiri, L. H. Omari, T. Mnasri, A. Benali, E. Dhahri, M. A. Valente
Summary: This study investigated the magnetic and magnetocaloric properties of lacunar compounds La1-xxMnO(3) using the Monte Carlo method and Ising model. The results obtained from simulations were in good agreement with experimental data. The compounds showed high relative cooling power values, making them promising materials for magnetic refrigeration technology and potential candidates for applications requiring high TC values.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Ceramics
A. F. Manchon-Gordon, J. S. Blazquez, M. Kowalczyk, J. J. Ipus, T. Kulik, C. F. Conde
Summary: In this study, the relaxation of the amorphous structure of mechanically alloyed Fe70Zr30 powders was analyzed through interrupted heating ramps below the devitrification temperature. The thermal treatment resulted in a shift of the Curie temperature and the temperature at maximum magnetic entropy change curves to higher temperatures, which can be attributed to both the release of accumulated stress in the amorphous powder and the initiation of nucleation of alpha-Fe crystallites.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2023)
Article
Physics, Applied
Simo Pajovic, Svetlana V. Boriskina
Summary: The magnetocaloric effect refers to the temperature change of a magnetic material caused by changes in its magnetization under the influence of an external magnetic field. This paper proposes an alternative thermal switch that combines the magnetocaloric effect with magneto-optical control of near-field radiative heat transfer, allowing for adjustable temperature gradient and conductance between two materials.
PHYSICAL REVIEW APPLIED
(2023)
Article
Chemistry, Physical
S. Kavita, M. Alagusoundarya, V. V. Ramakrishna, V Suresh, Pramod Bhatt, P. Srimathi, R. Archana, Debendranath Kar, Tiju Thomas, R. Gopalan
Summary: The properties of LaxFe11.6Si1.4 alloys prepared by arc melting were studied, showing that increasing La content leads to increased secondary phases and decreased 1:13 phase, as well as improved magnetic and mechanical properties. The alloys also exhibited a magnetocaloric effect and effective magnetic refrigeration capacity, making them suitable for potential magnetic refrigeration applications.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
Qingwei Wang, Hangfu Yang, Xinyao Luo, Jieyang Fang, Nengjun Yu, Qiong Wu, Minxiang Pan, Hongliang Ge
Summary: In this study, DyVO4 polycrystal was prepared by solid-state reaction, and the magnetization, magnetic phase transition, and structural phase transition were analyzed. It was found that Dy3+ undergoes a transition near 3.9 K, and the magnetic entropy change and refrigeration efficiency are affected by the magnetic field.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Yikun Zhang, Jianlong Ouyang, Xin Wang, Yun Tian, Zhongming Ren
Summary: In this work, Ti-doped Ni48Cu2Mn36Sn14-xTix ribbons were fabricated and studied to understand the magneto-structural transformations (MSTs) and improve the magnetocaloric performance of Hensler type Ni-Mn-Z (Z = Ga, In, Sn, or Sb) alloys. It was found that Ti doping can regulate the MSTs, enhance the magnetocaloric effect, and reduce thermal and magnetic hysteresis losses in these alloys.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Chemistry, Physical
Sebastian M. J. Beer, Arbresha Muriqi, Patrick Lindner, Manuela Winter, Detlef Rogalla, Michael Nolan, Andreas Ney, Jorg Debus, Anjana Devi
Summary: Europium sulfide (EuS) thin films grown via chemical vapor deposition (CVD) exhibit high quality, stoichiometry, and tunability, with the advantage of avoiding the use of toxic hydrogen sulfide.
CHEMISTRY OF MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Ning Liu, Teng Guo, Guo-Qing Yan, Guang Zhu, Huan-Yin Guo
Summary: In this study, the polycrystalline samples of La0.67-xNdxSr0.33MnO3 (x = 0.1, 0.2, 0.3, 0.4, 0.5) were prepared using the solid-state reaction method. The magnetic and transport properties of the samples were investigated. The results demonstrate that the magnetic structure of the samples transforms with the increase in Nd doping and phase separation occurs at certain doping levels. The transport properties also show variation with Nd doping, accompanied by the emergence of colossal magnetoresistance effect.
Article
Chemistry, Physical
G. Y. Lu, Y. S. Du, X. F. Wu, L. Ma, L. Li, G. Cheng, J. Wang, J. T. Zhao, G. H. Rao
Summary: In this paper, the crystal structure, magnetic phase transition, and magnetocaloric properties of the ErCo2-xCux (x = 0.12, 0.24, 0.36, and 0.48) compounds were investigated. The substitution of Cu for Co increased the Curie temperature and changed the magnetic phase transition type from first order to second order, resulting in an increased refrigerant capacity.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Bojun Zhao, Xiaojie Hu, Fuxiao Dong, Yan Wang, Haiou Wang, Weishi Tan, Dexuan Huo
Summary: This paper studied the magnetic behaviors and magnetocaloric effect of Pr0.7Sr0.3MnO3 (PSMO-7) film grown on a (001) SrTiO3 single-crystal substrate using pulsed laser deposition. The film showed a single orientation of (001) as observed by high-resolution X-ray diffraction. The temperature dependence of magnetization and magnetic field dependence of magnetization indicated a transition from paramagnetic to ferromagnetic state around the Curie temperature of approximately 193 K. The PSMO-7 film exhibited ferromagnetic properties at low temperatures and paramagnetic properties at higher temperatures. The maximum magnetic entropy change near the Curie temperature was found to be 4.7 J/kg K, indicating potential applications in magnetic refrigeration.
Article
Materials Science, Ceramics
Canglong Li, Shuangshuang Zheng, Yang Qiu, Qiankun Lei, Chunlei Wang, Yang Lu, Ya Yang, Hailong Yan, Yongsong Luo
Summary: In this study, double perovskite oxides Gd2NiMn1-xTixO6 were synthesized and their structural, magnetic, and cryogenic magnetocaloric properties were investigated. It was found that Ti substitution in Gd2NiMn1-xTixO6 progressively suppressed the ferromagnetic phase due to the dilution effect. The calculated values of magnetic entropy change and refrigeration capacity showed a similar trend, decreasing first and then increasing with increasing x, indicating the potential of Gd2NiMn1-xTixO6 for magnetic refrigeration applications.
CERAMICS INTERNATIONAL
(2023)
Article
Materials Science, Multidisciplinary
M. G. Kostenko, A. I. Gusev, A. V. Lukoyanov
Summary: Carbides of IV and V group transitional metals with B1 structure have been found to contain a large amount of vacancies in the carbon sublattice. The ordering of the vacancies can lead to the formation of new phases with various stoichiometry. In this study, the researchers investigate the new M7X6 type of vacancy-ordered structures in detail using ab initio methods. Two B1-derived vacancy-ordered phases, trigonal and monoclinic, are discovered for both Hf7C6 and Ta7C6 compounds. The trigonal ordered Hf7C6 phase is expected to have the highest Vickers hardness.
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
(2023)
Article
Chemistry, Physical
P. A. Igoshev, L. N. Gramateeva, A. V. Lukoyanov
Summary: In this study, the validity of standard magnetocaloric scenarios for a square lattice Hubbard model is revisited to describe a layered metal. Various types of magnetic ordering and their transitions are considered, as well as the phase-separated states formed by these first-order transitions. The entropy change in the phase separation regions is investigated in detail, revealing the existence of two characteristic temperature scales.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Inorganic & Nuclear
Yu. V. Knyazev, Yu. I. Kuz'min, S. T. Baidak, A. V. Lukoyanov
Summary: The electronic and optical properties of GdSb and TbSb, two binary semimetals in rocksalt cubic structure, were investigated. Spin-polarized band structure calculations were performed using the GGA + U method to account for electron correlations in rare-earth ions. The effects of spin-orbit interaction on the band structure were also studied. The calculated band features were found to be in good agreement with experimental data. It was shown that both GdSb and TbSb exhibit electron-hole compensation and have similar electronic structures. Additionally, a small pseudogap was observed in their densities of states. The energy dependencies of the complex dielectric permittivity for both materials were investigated through spectroscopic ellipsometry, and the experimental optical conductivity spectra were compared with the calculated ones.
SOLID STATE SCIENCES
(2023)
Article
Chemistry, Physical
Semyon T. Baidak, Alexey V. Lukoyanov
Summary: The electronic and band structures of ternary RNiSb and binary RSb compounds for R = Tb, Dy, Ho have been studied using an ab initio method. Ternary compounds are found to be semiconductors, while binary compounds exhibit semimetal properties. The magnetic moment of the compounds is determined by the magnetic moments of the rare-earth elements.
Article
Materials Science, Multidisciplinary
Anatoly G. Kuchin, Sergey P. Platonov, Roman D. Mukhachev, Alexey V. Lukoyanov, Aleksey S. Volegov, Vasilii S. Gaviko, Mari Yu. Yakovleva
Summary: The search for new magnetocaloric materials for magnetic refrigerants is driven by the desire for high efficiency, reliability, and environmental safety. The equiatomic GdRuSi compound was found to have high values of magnetocaloric effect (MCE) and refrigerant capacity (RC), at 10.7 and 4.94 J/kgK for MCE, and 336 and 92 J/kg for RC, with magnetic field changes of 0-50 and 0-17 kOe, respectively. These high values occur around the nitrogen liquefaction temperature of 77.4 K, indicating potential practical use. Theoretical calculations of densities of states and magnetic moments show that the total magnetic moment of GdRuSi is contributed solely by the Gd moment, in good agreement with experimental findings.
Article
Physics, Applied
Svetlana G. Titova, Alexey S. Shkvarin, Alexey V. Lukoyanov, Stepan V. Pryanichnikov, Ratibor G. Chumakov, Alexander M. Lebedev, Ludmila P. Kozeeva, Margarita Yu. Kameneva, Vladimir E. Fedorov
Summary: The connection between the density peak of electronic states and the localization of charge carriers at the compression of CuO5 pyramids in Y0.9Ca0.1Ba2Cu3O6.8 single crystal is found through a comparison of experimental angle-resolved photoemission spectra data and electronic structure calculations using density functional theory. Both experiment and calculation are performed using photon energies of 34.6 and 90.2 eV. Excitation energy does not affect the density peak of electronic states. Crystal structure distortions on the surface result in the observation of localized electronic states below the superconducting transition temperature.
JOURNAL OF SUPERCONDUCTIVITY AND NOVEL MAGNETISM
(2023)
Article
Materials Science, Multidisciplinary
Yu. V. Knyazev, A. V. Lukoyanov, Yu. I. Kuz'min, Shubhra Dash, Ajit K. Patra, M. Vasundhara
Summary: This paper presents electronic spectrum calculations and a study of the optical properties of binary compounds Mn70Al30 and Mn80Al20. The high values of the calculated density of states at the Fermi level are determined by broad bands formed by manganese 3d states. The measured optical conductivity spectra of the alloys are analyzed using the calculated electronic structures, and various characteristics of conduction electrons are evaluated based on their optical properties in the infrared spectral region.
INORGANIC MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
A. N. Filanovich, A. A. Povzner, A. V. Lukoyanov
Summary: Based on the gradient boosting method, regression models are constructed to rapidly predict the lattice thermal conductivity and other thermal and elastic properties of double half-Heusler compounds. These models have allowed for the calculation of properties that were previously difficult to study directly. The results show good agreement with experimental data.
MATERIALS CHEMISTRY AND PHYSICS
(2023)
Article
Physics, Applied
Yu. V. Knyazev, A. V. Lukoyanov, Yu. I. Kuz'min
Summary: The optical properties of ScGa3 and LuGa3 superconducting binary compounds were investigated for the first time, and the results were explained in terms of the band structure. Calculations and measurements showed that both materials exhibited strong absorption in the dielectric functions spectra, which agreed with the calculated metal-like energy structures. The characteristics of quantum light absorption were discussed based on a comparative analysis of experimental and theoretical interband optical conductivity spectra, and the plasma and relaxation frequencies of conduction electrons were determined.
MODERN PHYSICS LETTERS B
(2023)
Article
Physics, Condensed Matter
A. N. Filanovich, A. V. Lukoyanov, A. A. Povznera
Summary: Double half Heusler alloys are promising materials for thermoelectric power converters. In this study, the lattice thermal conductivity of 118 such alloys was predicted using machine learning, and five compositions with the lowest thermal conductivity were identified. The electronic and elastic properties of these alloys were then studied, and it was found that three of them have a small band gap width, indicating excellent electronic thermoelectric properties. Additionally, the analysis of the elastic characteristics showed that these alloys are ductile and have low anisotropy of the elastic properties.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Metallurgy & Metallurgical Engineering
E. I. Shreder, A. N. Filanovich, E. D. Chernov, A. V. Lukoyanov, V. V. Marchenkov, L. A. Stashkova
Summary: The electronic structure, thermoelectric characteristics, and experimental study of Mn2MeAl Heusler alloys (Me = Ti, V, Cr) are presented. The agreement between theory and experiment in the sign of the Seebeck coefficient is shown. The obtained band spectrum pattern allows for a qualitative explanation of the temperature dependences of the electrical resistance and the permittivity dispersion.
PHYSICS OF METALS AND METALLOGRAPHY
(2023)
Article
Chemistry, Analytical
Vyacheslav V. Marchenkov, Alexey V. Lukoyanov, Semyon T. Baidak, Alexandra N. Perevalova, Bogdan M. Fominykh, Sergey V. Naumov, Elena B. Marchenkova
Summary: This study investigates the electrical resistivity and the Hall effect of topological insulator Bi2Te3 and Bi2Se3 single crystals. The results show a clear correlation between the density of electronic states at the Fermi level and the current carrier concentration. With increasing temperature, the density of states and the carrier concentration increase for Bi2Te3, while they decrease for Bi2Se3.
Article
Chemistry, Multidisciplinary
Stanislav I. Sadovnikov, Maksim G. Kostenko, Aleksandr I. Gusev, Aleksey V. Lukoyanov
Summary: In this study, the evolutionary algorithm was used for the first time to perform a broad search for low-temperature Ag2S phases of silver sulfide. It was found that the formation of low-symmetry Ag2S phases is energetically most favorable. The mechanical stability and electronic state densities of these predicted Ag2S phases were also calculated. These findings indicate the possibility of synthesizing new silver sulfide phases with improved properties.
Article
Chemistry, Inorganic & Nuclear
Evgeniy D. D. Chernov, Alexey V. V. Lukoyanov
Summary: In this theoretical study, the effect of electron correlations on the electronic structure and magnetic properties of Mn2NiAl alloy was investigated using first-principles calculations. Hybrid functional (HSE) and DFT+U methods were employed to study the electron correlation effect with a range of parameter values. The results showed that the manganese ions' magnetic moment increased with an increase in the Coulomb interaction parameter, while the total magnetic moment decreased due to antiferromagnetic ordering of the Mn ions and small magnetic moment of Ni. The calculated total magnetic moment agreed well with experimental results, and the compound remained metallic in its electronic structure.
Article
Chemistry, Physical
A. G. Kuchin, S. P. Platonov, R. D. Mukhachev, A. V. Lukoyanov, A. S. Volegov, V. S. Gaviko, M. Yu. Yakovleva
Summary: Intermetallic compounds GdFe1-xCrxSi, GdFe1-xVxSi, and GdFe1-xNixSi with a tetragonal CeFeSi structure type have been synthesized and their properties studied. The changes in Curie temperature can be attributed to changes in the density of states. The electronic structure, magnetic moments, and magnetic orderings of these compounds were calculated using a theoretical method. The transformation of GdFe1-xNixSi from a ferromagnet to an antiferromagnet was observed experimentally and confirmed by calculations. The compounds GdFe0.4Cr0.6Si and GdFe0.7V0.3Si with their Curie temperatures close to room temperature could be of practical interest.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
