Article
Chemistry, Multidisciplinary
M. Saidi, H. Jaballah, L. Bessais, M. Jemmali
Summary: The effect of substituting iron with chromium on the structural, magnetic, and magnetocaloric behaviors of Gd2Fe17-xCrx compounds was investigated. The substitution increased the unit-cell volume and lowered the Curie temperature. The compounds exhibited a magnetic to paramagnetic transition and showed potential for use in magnetic refrigeration and heat pumping technology.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2023)
Article
Chemistry, Physical
Hongguang Zhang, Hu Qian, Liang Xie, Yanyan Guo, Yuzhuang Liu, Xuemin He
Summary: Non-magnetic Ga3+ doping in HoCrO3 triggers a new spin-reorientation transition and changes the crystal structure, electronic structure, Raman spectra, and magnetic behaviors. The dilution of magnetic couplings and appearance of complex magnetic transitions are observed with Ga3+ doping. Additionally, Ga3+ doping improves the magneto-caloric effect and refrigerant capacity, providing insights for optimizing MCE properties.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
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
Engineering, Electrical & Electronic
Jayalekshmi Mini, Navya Joseph, Rahul Sugathan, Chinnu Vasu Devan, Imaddin A. Al-Omari, Manoj Raama Varma, Senoy Thomas
Summary: Y-type hexaferrite Ba0.5Sr1.5Zn2-xNixFe12O22 (x = 0, 0.5, 1.0, and 1.5) was synthesized and the effect of Zn2+ ion substitution with Ni2+ ions on the magnetic spin transition temperature was studied. X-ray diffraction confirmed the formation of Y-type hexaferrite phase. The lattice contracted with an increase in Ni-ion content. Scanning electron microscopy analysis revealed hexagonal-shaped grains with particle sizes ranging from 2-8 μm. Temperature-induced magnetic transitions were observed in all compositions. M-T measurements showed that the ferrimagnetic to paramagnetic transition temperature could be tuned from 510 to 750 K via Ni2+ ion substitution. Furthermore, magnetic field-induced spin phases were evident through the multistage hysteresis observed in the M-H loops for x = 0.5 and 1.5.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2023)
Article
Materials Science, Ceramics
Donglei Wei, Xifeng Yang, Yushen Liu, Hyo Jin Seo
Summary: Structural and optical properties of Mg1-xMnxP2O6 compounds were investigated. The compounds exhibit a monoclinic crystal structure, and a significant change in the optical properties was observed when x = 0.5. The research highlights the importance of MnO6 octahedral distortions in the luminescence properties of Mn2+ activators.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Materials Science, Multidisciplinary
K. Nouri, M. Saidi, L. Bessais, M. Jemmali
Summary: The study explores the magnetic properties and structural characteristics of Sm2Fe17-xNix alloys with different compositions, revealing a second-order ferromagnetic to paramagnetic phase transition near the Curie temperature. The alloys exhibit increasing magnetic entropy change Delta SM and relative cooling power with higher Ni content, with a significant temperature range contributing to larger Delta SM values.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Article
Materials Science, Ceramics
Mehrnoush Nakhaei, Marcos A. L. Nobre, Davoud Sanavi Khoshnoud, Martin Bremholm, Hossein Ali Khonakdar
Summary: Crystalline and single-phase Y1-xScxFeO3 (x = 0, 0.5 & 1) nanoparticles were synthesized by sol-gel method. The nanocrystals had sizes ranging from 30 to 39 nm as determined by X-Ray Diffractometry (XRD). The morphology and surface characteristics of the samples were analyzed using Field Emission Scanning Electron Microscopy (FE-SEM) and energy dispersive spectroscopy (EDS). The magnetic properties of the samples exhibited antiferromagnetic and paramagnetic behaviors, while the electrical properties showed polarization-electric loops, dielectric constant changes, and dielectric loss through frequency and temperature. The band gap energy of YFeO3 and ScFeO3 was calculated to be 2.97 and 3.07 eV, respectively, using diffuse reflectance spectroscopy analysis.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Physical
V Paul-Boncour, K. Provost, T. Mazet, A. N'Diaye, E. Alleno, F. Couturas
Summary: At different temperatures, the structures and magnetic properties of Y0.9Gd0.1Fe2Hx hydrides change sequentially. Above 300K, they undergo a first-order transition and exhibit negative and positive magnetic entropy variations. The proposed structural and magnetic phase diagram provides a better understanding of the properties of these hydrides.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Computer Science, Information Systems
Sergei V. Zubkov, Ivan A. Parinov, Yulia A. Kuprina
Summary: A new series of layered perovskite-like oxides Bi3-xNdxTi1.5W0.5O9 (x = 0.25, 0.5, 0.75, 1.0) with partial substitution of bismuth by neodymium atoms was successfully synthesized by high-temperature solid-state reaction. The compounds have a single-phase structure and show good properties in terms of structural characteristics and relative permittivity.
Article
Materials Science, Ceramics
Daneshwaran Balaji, Sathasivam Pratheep Kumar
Summary: Incorporating cesium into orthorhombic langbeinite phosphosilicate has been shown to be feasible, with low crystallinity and significant impact on thermal expansion.
CERAMICS INTERNATIONAL
(2021)
Article
Materials Science, Ceramics
Feng Li, Mingsheng Long, Chunchang Wang, Jiwei Zhai
Summary: In this study, relationships between phase structure, dielectric, and ferroelectric performances in the (Pb, Ba)ZrO3 system were meticulously explored to clarify its complex characteristics. The observed ferroelectric behaviors were found to be substantially influenced by domain switching, and a phase diagram was constructed to guide compositional design in this system.
CERAMICS INTERNATIONAL
(2021)
Article
Materials Science, Multidisciplinary
I. M. Saavedra Gaona, E. Moncada-Villa, C. A. Ortiz-Otalora, J. Munevar, C. A. Parra Vargas
Summary: We conducted a systematic study on the structural and magnetic properties of LaBa1-xSrxCuFeO5+delta (La -x) and YbBa1-xSrxCuFeO5+delta (Yb-x) ceramic compounds. The experimental results show that the crystal structure, infrared spectrum, surface morphology, and composition of the materials change with different Sr contents. Vibrating sample magnetometry measurements indicate the presence of an antiferromagnetic transition only when x = 0.
MATERIALS CHARACTERIZATION
(2022)
Article
Chemistry, Inorganic & Nuclear
Y. Marouani, A. Mabrouki, R. Dhahri, E. Dhahri, B. F. O. Costa
Summary: Nanopowder hexaferrites (Ba1-xSrxFe12O19) with varying Sr rates were synthesized, characterized, and their magnetic properties were evaluated. The results showed an enhancement of magnetic properties with increasing Sr rate and indicated a semiconductor behavior. The authors also calculated various magnetic parameters and determined the energy anisotropy and anisotropy constant, both of which increased with increasing Sr rate.
INORGANIC CHEMISTRY COMMUNICATIONS
(2022)
Article
Materials Science, Ceramics
Yuzhou Xiao, Fengjiao Qian, Xin Gao, Run Zhao, Xuefei Miao, H. Yang
Summary: The study successfully fabricated MnCoGe-based thin films using the pulsed laser deposition technique and found that the annealed film showed reversible magnetic-structural transitions at 250°C, resulting in a reversible magnetocaloric effect.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Physical
Chun Sheng Fang, Jian Li Wang, Wayne D. Hutchison, W. Q. Wang, A. J. Studer, Q. F. Gu, Jinkui Zhao
Summary: Negative to positive thermal expansion transition was detected with increasing Mn content in HoCo2Mnx below the Curie temperature through neutron diffraction measurements. Almost isotropic zero thermal expansion was achieved in HoCo2Mn0.5 over a large temperature range. The addition of manganese not only changed the temperature dependence of the lattice, but also significantly increased the Curie temperature in HoCo2Mn.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Multidisciplinary
Stephen E. Brown, Ioanna Mantaloufa, Ryan T. Andrews, Thomas J. Barnes, Martin R. Lees, Frank De Proft, Ana V. Cunha, Sebastian D. Pike
Summary: The molecular titanium-oxo cluster [Ti6O6((OPr)-Pr-i)(6)((O2CBu)-Bu-t)(6)] (1) can be activated by UV light to produce a mixed valent (photoreduced) Ti (iii/iv) cluster, along with alcohol and ketone organic products. Mechanistic studies show a two-electron mechanism utilizing the cluster structure for multielectron reactions. The photoreduced products [Ti6O6((OPr)-Pr-i)(4)((O2CBu)-Bu-t)(6)(sol)(2)] can be isolated and characterized, and undergo onward oxidation under air. The redox reactivity described is only possible in a cluster with multiple Ti sites.
Article
Chemistry, Multidisciplinary
Robyn E. Powell, Martin R. Lees, Graham J. Tizzard, Simon J. Coles, Qingchun Yuan, Petra J. van Koningsbruggen
Summary: The synthesis and crystal structure (100 K) of the compound [(CH3)(2)NH2]-[Fe(C10H11O2N3S)(2)] are reported. The structure consists of an octahedral [Fe-III (L)(2)](-) fragment and a dimethylammonium cation. Each L2- ligand binds to the FeIII ion through the S, N, and O atoms, forming an (FeS2N2O2)-S-III chromophore. The ligands are arranged in two perpendicular planes, with the O and S atoms in cis positions and the N atoms in trans positions. The magnetic measurements confirm the presence of a high-spin Fe-III ion with D = 0.83 (1) cm(-1) and g = 2 at 100 K.
ACTA CRYSTALLOGRAPHICA SECTION C-STRUCTURAL CHEMISTRY
(2023)
Article
Engineering, Environmental
Sayan Pal, Maximilian O. Besenhard, Liudmyla Storozhuk, Martin R. Lees, Nguyen Thi Kim Thanh, Asterios Gavriilidis
Summary: This work demonstrates a modular triphasic flow reactor platform that enables continuous and fouling-free four-step co-precipitation flow synthesis of iron oxide nanoparticles (IONPs) for magnetically induced hyperthermia cancer treatment (MHCT). By using a seeded growth co-precipitation strategy and a nitrogen gas spacer, the flow platform allows for the continuous synthesis of colloidally stable IONPs with high heating performance in a short residence time.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Inorganic & Nuclear
Lu Jia, Matthew D. Lloyd, Martin R. Lees, Limin Huang, Richard I. Walton
Summary: In this study, the crystallization of a new series of A-site substituted lanthanum ferrite materials (La1-xREx)FeO3 was explored using hydrothermal method. The effect of elemental substitution on the morphological, structural, and magnetic properties of the materials was studied. It was found that homogeneous solid solutions are formed when La3+ and substituent ions have similar radii, while crystallization in separate phases is found when there is a large radius difference. A-site replacement induces an evolution in the crystallite shape, providing evidence for a phase-separation-driven evolution of morphology.
INORGANIC CHEMISTRY
(2023)
Article
Physics, Condensed Matter
Rukang Li
Summary: The electronic structure and vibrational spectra of ferroelectric LiNbO3 crystal (LN) are calculated using the CRYSTAL program. The obtained results include the bandgap, refractive indices, and nonlinear optical coefficients. It is found that the phonon vibrations in LN are asymmetric along the polar axis and the calculated frequencies strongly depend on displacement parameters. The calculated vibrational frequencies agree well with the measured ones, except in a certain frequency range.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2023)
Article
Engineering, Manufacturing
Kun Sun, Abd El-Moez A. Mohamed, Sheng Li, Minki Jeong, Jake Head, Moataz M. Attallah
Summary: This study aims to develop a low-cost dense magnetocaloric Ni-Mn-Sn Heusler alloy (HA) using laser powder bed fusion (LPBF) additive manufacturing. The highest density was achieved at laser energy densities of 18.52 J/mm(3), 53.33 J/mm(3), and 89.89 J/mm(3) with densities of 6.8 g/cm(3), 8.2 g/cm(3), and 8.3 g/cm(3), respectively. The samples exhibited the L2(1) phase and double magnetic transitions, martensitie-austenite transition (T-M) and curie temperature (T-C(A)), with high magnetic entropy change values at T-M and T-C(A).
ADDITIVE MANUFACTURING
(2023)
Article
Materials Science, Multidisciplinary
Rukang Li
Summary: This paper investigates the electro-optic effects of barium borate, potassium titanyl phosphate, and rubidium titanyl phosphate crystals through ab initio calculations. The results show good agreement between the calculated electro-optic coefficients and experimental values, and the contribution of vibrational modes to the electro-optic effect is significant.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Article
Chemistry, Inorganic & Nuclear
Changqing Zhou, Rukang Li
Summary: The lone pair electrons in Bi(3+) result in a significant difference in second harmonic generation (SHG) response between Bi3TeBO9 and its isomorphic compound RE3TeBO9. However, compared to Bi3TeBO9, RE3TeBO9 exhibits a smaller SHG effect, which may be attributed to the misalignments and lack of distortions of the structural units [BO3], [TeO6], and [REO8] within the unit cell.
INORGANIC CHEMISTRY
(2023)
Article
Materials Science, Multidisciplinary
Amelia E. Hall, Pascal Manuel, Dmitry D. Khalyavin, Fabio Orlandi, Daniel A. Mayoh, Lieh-Jeng Chang, Yu-Sheng Chen, David G. C. Jonas, Martin R. Lees, Geetha Balakrishnan
Summary: The Mn3XY family of materials, with ordered chiral beta-Mn structure, displays different magnetic behaviors, with Mn3RhGe exhibiting a high-temperature incommensurate magnetic structure transitioning into a noncollinear commensurate antiferromagnetic ground state, while Mn3IrSi shows a noncollinear commensurate magnetic structure at all temperatures.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
G. D. A. Wood, D. D. Khalyavin, D. A. Mayoh, J. Bouaziz, A. E. Hall, S. J. R. Holt, F. Orlandi, P. Manuel, S. Bluegel, J. B. Staunton, O. A. Petrenko, M. R. Lees, G. Balakrishnan
Summary: We investigate the magnetic structure of GdRu2Si2 using neutron diffraction and discover higher-order magnetic satellites. We refine a double-Q constant-moment model using powder diffraction and find that the structure contains vortexlike motifs with a one-dimensional topological charge density.
Article
Materials Science, Multidisciplinary
Ashish Kumar Mishra, S. Shanmukharao Samatham, Mark T. F. Telling, A. D. Hillier, Martin R. Lees, K. G. Suresh, V. Ganesan
Summary: We have observed the presence of magnetic rare regions in Fe-doped MnSi that exhibit the quantum Griffiths phase. These rare regions exhibit slow dynamics at low temperatures, resulting in non-Fermi-liquid behavior in heat capacity and magnetization. Our μSR and magnetization measurements indicate that the dynamics freeze into a cluster-glass state below Tf around 1.25 K. These findings are consistent with theoretical models proposed for metallic systems with Heisenberg symmetry and strong disorder exhibiting the quantum Griffiths phase.
Article
Chemistry, Multidisciplinary
Changqing Zhou, Rukang Li
Summary: The newly obtained compound Gd3TeBO9 has a high Gd3+ concentration and a large magnetic entropy change, showing its potential for further development as a magnetocaloric material.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Wilgner Lima da Silva, Ashok S. Menon, Martin R. Lees, Reza J. Kashtiban, Marc Walker, Louis F. J. Piper, Emma Kendrick, Richard I. Walton
Summary: A Mn2+-Li-Nb disordered rock-salt oxide cathode is prepared by a solid-state reaction under 5% H-2/N-2 atmosphere, showing a high voltage plateau and irreversible structural changes in the first cycle.
CHEMICAL COMMUNICATIONS
(2023)
Article
Physics, Atomic, Molecular & Chemical
Murari Soundararajan, George R. Bacanu, Francesco Giustiniano, Mark C. Walkey, Gabriela Hoffman, Marina Carravetta, Martin R. Lees, Richard J. Whitby, Malcolm H. Levitt
Summary: This article presents a new variant of the superconducting fulleride Rb3C60, with He-3 atoms encapsulated in the C-60 cages. The characteristics of the superconducting and normal states are examined using He-3 NMR. Evidence is found for the coexistence of vortex liquid and vortex solid phases below the superconducting transition temperature. The spin-lattice relaxation time constant in the superconducting state shows a strong dependence on spectral frequency, which is revealed by two-dimensional NMR using an inverse Laplace transform. Surprisingly, this phenomenon persists, in attenuated form, at temperatures well above the superconducting transition.
APPLIED MAGNETIC RESONANCE
(2023)
Article
Chemistry, Inorganic & Nuclear
Ziyan Lv, Rukang Li
Summary: In this study, a tantalum phosphate crystal Na11Ta8P7O43 with a moderate second harmonic response was synthesized using self-fluxes method. The crystal was found to have unique structural features and moderate nonlinear effects. It exhibits phase-matchable second harmonic generation, a shorter cutoff edge than known materials LiTaO3 and KTiOPO4, and high transmittance in the visible to near infrared band, suggesting its potential as a nonlinear optical crystal.
DALTON TRANSACTIONS
(2023)