Article
Chemistry, Physical
Xiaoxuan Ma, Wencheng Fan, Gang Zhao, Haiyang Chen, Chuankun Wang, Baojuan Kang, Zhenjie Feng, Jun-Yi Ge, Wei Ren, Shixun Cao
Summary: The magnetic behavior of a rare-earth orthoferrite ErFeO3 single crystal can be controlled by low magnetic fields, with two types of spin switching observed below the spin reorientation transition temperature. The applied magnetic fields can regulate the spin switching along the a-axis of the single crystal, while understanding the magnetic reversal effects can help explore potential applications in information devices.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Shulan Zuo, Kaiming Qiao, Ying Zhang, Tongyun Zhao, Chengbao Jiang, Baogen Shen
Summary: Using atomic chemical environment switching, we demonstrate the spontaneous existence of magnetic biskyrmions at room temperature in Nd 1-x Tb x Co 5 ( x = 0.3, 0.5) alloys. High-density biskyrmions are stimulated to form in the thinner region at room temperature by introducing an in-plane magnetic field component. These results provide valuable insights into the manipulation of topological states and are of great significance to practical applications.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
Gang Zhao, Wencheng Fan, Haiyang Chen, Xiaoxuan Ma, Baojuan Kang, Wenlai Lu, Jincang Zhang, Shixun Cao
Summary: The large single crystal Dy0.5Er0.5FeO3 shows spin switching behavior in a wide temperature range, with the occurrence of magnetization drop in field-cooling (FC) mode and magnetization jump in zero-field-cooling (ZFC) mode under low magnetic fields. The spin reorientation transition and spin switching in Dy0.5Er0.5FeO3 single crystal are governed by magnetic interactions between (Dy, Er)-4f and Fe-3d electrons in different sublattices.
APPLIED MATERIALS TODAY
(2021)
Article
Materials Science, Multidisciplinary
S. A. Skorobogatov, K. A. Shaykhutdinov, D. A. Balaev, M. S. Pavlovskii, A. A. Krasikov, K. Yu. Terentjev
Summary: The low-temperature spin dynamics of the orthorhombic TbFeO3 perovskite has been studied. It has been found that the iron subsystem exhibits antiferromagnetic order at 632 K and shows high-energy magnon dispersion. The behavior of the magnetic correlation length of the terbium subsystem has been determined through studying diffuse scattering at different temperatures.
Article
Chemistry, Physical
Zhiqiang Sun, Huan Song, Shuang Zhu, Xiaoxuan Ma, Wanting Yang, Chenfei Shi, Baojuan Kang, Rongrong Jia, Jin-Ke Bao, Shixun Cao
Summary: We have prepared single crystal Nd0.8Pr0.2FeO3 and investigated the effect of Pr-doping on its magnetic properties. The Pr-doping lowered the spin reorientation transition temperature range and exhibited excellent properties in spin switching. Different types of spin switching events were observed in Nd0.8Pr0.2FeO3, and a significant magnetic entropy change was observed at low temperatures and high magnetic fields.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Zhiqiang Sun, Huan Song, Shuang Zhu, Xiaoxuan Ma, Wanting Yang, Chenfei Shi, Baojuan Kang, Rongrong Jia, Jin-Ke Bao, Shixun Cao
Summary: Single crystal Nd0.8Pr0.2FeO3 was prepared using the optical floating zone method, and the effect of Pr-doping on its magnetic properties was investigated. 20% Pr3+ doping exhibited superior spin switching performance at lower temperatures. These results provide a better understanding of the doped magnetic anisotropy in RFeO3 and offer new possibilities in the application of magnetic switching materials under low magnetic fields.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Materials Science, Multidisciplinary
J. Okamoto, A. Chainani, Z. Y. Chen, H. Y. Huang, A. Singh, T. Sasagawa, D. I. Khomskii, A. Fujimori, C. T. Chen, D. J. Huang
Summary: In this study, x-ray spectral evidence is presented for the evolution of valence- and spin-specific tetragonal distortions in single-layer cobaltates. The measurements reveal changes in tetragonal splitting of high-spin Co2+ and low-spin Co3+ states as Sr-doping increases, shedding light on the origin of magnetic anisotropy and in-plane resistivity changes in mixed-valence cobaltates.
Article
Chemistry, Multidisciplinary
Shulan Zuo, Jun Liu, Kaiming Qiao, Ying Zhang, Jie Chen, Na Su, Yanli Liu, Jun Cao, Tongyun Zhao, Jingmin Wang, Fengxia Hu, Jirong Sun, Chengbao Jiang, Baogen Shen
Summary: The study observed the spontaneous generation of skyrmions and the unique topological domain evolution during spin reorientation in a neodymium-cobalt (NdCo5) rare-earth magnet. As the temperature decreases, nanoscale skyrmion lattices evolve into enclosed in-plane domains (EIPDs), resembling mini bar-magnets with size below 120 nm.
ADVANCED MATERIALS
(2021)
Article
Chemistry, Physical
Xiaoxuan Ma, Rongrong Jia, Gang Zhao, Shuang Zhu, Wanting Yang, Wencheng Fan, Haiyang Chen, Baojuan Kang, Jin-Ke Bao, Shixun Cao
Summary: The introduction of Yb ions into SmFeO3 single crystal can modulate the spin reorientation transition temperature and enhance the magnetization compensation temperature. Different spin switching effects can be observed under applied magnetic fields, including a unique spin switching phenomenon at lower magnetic fields during room temperature spin reorientation.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Physics, Multidisciplinary
Protyush Nandi, Sirshendu Bhattacharyya, Subinay Dasgupta
Summary: Quantum phase transitions occur at zero temperature when quantum fluctuations destroy order. At finite temperatures, a physical quantity displaying nonanalytic behavior can emerge when an interaction parameter crosses the boundary line of the quantum phase transition. This quantity is the long time limit of a form of quantum fidelity.
PHYSICAL REVIEW LETTERS
(2022)
Article
Materials Science, Ceramics
Huan Song, Wencheng Fan, Rongrong Jia, Zhiqiang Sun, Xiaoxuan Ma, Wanting Yang, Shuang Zhu, Baojuan Kang, Zhenjie Feng, Shixun Cao
Summary: A high-quality TmFeO3 single crystal with a length of 50 mm was successfully prepared using a four-mirror optical floating zone furnace. The crystal's quality and orientation were determined using an X-ray diffractometer and Laue back reflection camera. The magnetic properties of the crystal were systematically studied, revealing a spin reorientation transition and temperature-induced spin switching not previously reported. These findings suggest the crystal's potential application in future spintronic devices, as the triggering temperatures of the spin switching can be controlled by adjusting external magnetic fields.
CERAMICS INTERNATIONAL
(2023)
Article
Physics, Applied
Jiawang Xu, Zhan Wang, Zhuolin Li, Yang Gao, Chaoqun Hu, Dingsong Wang, Jingyan Zhang, Xinqi Zheng, Jianwang Cai, Tongyun Zhao, Shouguo Wang, Ying Zhang, Baogen Shen
Summary: Exploring and discovering various types of skyrmions has enriched the study of spintronics and its application in high-density magnetic information storage. The interactions between 4f and 3d electrons in rare-earth-transition metal magnets have led to the discovery of exotic magnetic domain configurations. Manipulating the magnetic anisotropy has allowed for the generation of field-free biskyrmions and tunable spin texture transformation, expanding the understanding of manipulating ferrimagnetic order and generating topological spin structures in rare-earth magnets.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Physics, Multidisciplinary
Wencheng Fan, Haiyang Chen, Gang Zhao, Xiaoxuan Ma, Ramki Chakaravarthy, Baojuan Kang, Wenlai Lu, Wei Ren, Jincang Zhang, Shixun Cao
Summary: In PrFe1-xMnxO3 single crystals, the spin reorientation transition temperature can be modulated by varying the Mn concentration, which is of great importance for spin control.
FRONTIERS OF PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Lingling Wang, Linwen Jiang, Jiamin Shang, Jiangtao Li, Liangbi Su, E. D. Mishina, Anhua Wu
Summary: Single crystal Er0.4Gd0.6FeO3 (EGFO) with special magnetic characteristics, including nonzero spontaneous magnetic moment along crystalline b-axis and 2-fold spin reorientation transition, was grown by optical floating-zone method. The phenomenon is unusual for most of rare-earth orthoferrites and the transition result from the competitions of different interactions at different temperature areas. The work is meaningful for further studying the physical phenomenons in RFeO3 and their potential applications.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Engineering, Chemical
Abderraouf Soukeur, Anthony Szymczyk, Yassine Berbar, Mourad Amara
Summary: This study experimentally validated the feasibility of extracting rare earth elements from industrial waste, identified optimal extraction conditions and methods, and investigated the effects of two organic phosphorous extractants in the separation process of rare earth elements.
SEPARATION AND PURIFICATION TECHNOLOGY
(2021)
Article
Materials Science, Multidisciplinary
Ling Qiao, R. Ramanujan, Jingchuan Zhu
Summary: This study implemented a machine learning approach to investigate the relationship between temperature, alloying elements, and yield strength in multi-component alloys. Based on the findings, AlxCrFeNi medium-entropy alloys (MEAs) were developed, which exhibited a two-phase structure formed through spinodal decomposition mechanism. The mechanical properties of the developed MEAs, particularly with high Al content, showed significant improvement at elevated temperatures. The oxidation behavior and mechanism of the AlxCrFeNi MEAs (x > 0.8) at 1000 degrees C were also explored. Overall, this work has identified a promising family of MEAs that offer low density and excellent mechanical properties for high temperature structural applications.
Article
Chemistry, Physical
Ling Qiao, R. Ramanujan, Jingchuan Zhu
Summary: This study investigated the hot compressive deformation behavior of Co-free Fe2.5Ni2.5CrAl multi-principal element alloys and determined the optimum processing parameters, as well as revealed the main deformation mechanism.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
Ling Qiao, R. V. Ramanujan, Jingchuan Zhu
Summary: In this study, the microstructure, hardness, and wear resistance of Fe2Ni2CrAl multi-principal elements alloy were investigated. The alloy showed a dual-phase structure and exhibited good wear resistance. Molecular dynamics simulations were also utilized to analyze the wear behavior at the nanoscale. The findings provided valuable insights into the wear mechanisms of Fe2Ni2CrAl alloys.
JOURNAL OF MATERIALS SCIENCE
(2023)
Article
Nanoscience & Nanotechnology
V. Chaudhary, M. S. K. K. Y. Nartu, S. Dasari, S. M. Varahabhatla, A. Sharma, M. Radhakrishnan, S. A. Mantri, S. Gorsse, N. B. Dahotre, R. V. Ramanujan, R. Banerjee
Summary: Varying the Al content significantly influences the microstructure, magnetic properties, and microhardness of Alx(CoFeNi) (x = 0, 10, 30) complex concentrated alloys. The heat treated Al10(CoFeNi) CCA exhibited improved saturation magnetization, Curie temperature, and microhardness due to its hierarchical FCC/L12+BCC/B2 heterostructure. However, there was no significant change in the properties of heat treated CoFeNi and Al30(CoFeNi) CCA. These findings can be explained by thermodynamic modeling of phase stability.
SCRIPTA MATERIALIA
(2023)
Article
Materials Science, Multidisciplinary
Andras Kovacs, Nithin B. Venkataraman, Varun Chaudhary, Sriswaroop Dasari, Thibaud Denneulin, R. V. Ramanujan, Rajarshi Banerjee, Rafal E. Dunin-Borkowski
Summary: The microstructural features significantly affect the coercivity of magnetic alloys. While the influence of homophase boundaries on magnetic domain wall pinning is well understood, the role of heterophase interfaces on domain wall motion is complex and not well known. This study used advanced electron microscopy techniques to reveal the dramatic changes in the magnetization reversal process in an Al0.3CoFeNi magnetic complex concentrated alloy (CCA) and its impact on coercivity. The heterophase FCC/BCC interfaces were found to have a stronger effect on coercivity compared to isostructural chemically ordered/disordered interfaces, providing valuable insights for the rational design of microstructure in magnetic alloys.
Article
Engineering, Mechanical
Xuesong Xu, Hongsheng Ding, Haitao Huang, He Liang, R. V. Ramanujan, Ruirun Chen, Jingjie Guo, Hengzhi Fu
Summary: The deformation mechanism responsible for the high-cycle rotating bending fatigue of a high-Nb TiAl alloy was studied. Superlattice dislocations [0 1 1] and twinning dominated the fatigue deformation in the gamma phase. Dislocations 11 0 in the B2 phase were induced by twins in the adjacent gamma phase due to the low stacking fault energy caused by the high Nb content. Stress transfer between adjacent phases was achieved through atomic rearrangement of the interface by twinning. Local stresses were accommodated by continuous dislocation slip in the B2 phase, deformation twins, and twin intersections in the gamma phase.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Nanoscience & Nanotechnology
M. Radhakrishnan, M. McKinstry, V. Chaudhary, M. S. K. K. Y. Nartu, K. V. Mani Krishna, R. V. Ramanujan, R. Banerjee, Narendra B. Dahotre
Summary: The soft magnetic behavior of CoCrxFeNi alloys deposited by laser directed energy deposition was studied. It was found that the saturation magnetization of these alloys decreased with increasing Cr content and exhibited paramagnetic behavior at room temperature. The Curie temperature of the ferromagnetic CoFeNi alloy linearly decreased with Cr content, while the paramagnetic equiatomic alloy had a ferromagnetic transition temperature of 94 K. The as-deposited alloys showed low coercivity values irrespective of the Cr content. The results suggest that the magnetic behavior of the CoFeNi alloy can be tuned with the addition of antiferromagnetic Cr, and the additive manufacturing route is effective for rapidly processing alloys with desired compositions.
SCRIPTA MATERIALIA
(2023)
Article
Materials Science, Multidisciplinary
V. Sharma, X. Tan, P. S. Sankara Rama Krishnan, Sravya Tekumalla, M. Duchamp, Xuesong Xu, Hongsheng Ding, V. Chaudhary, R. V. Ramanujan
Summary: Bulk Ti-48Al alloy samples were prepared by high energy ball milling and spark plasma sintering, and their microstructure, phase evolution and mechanical properties were studied. The resulting alloy exhibited an equiaxed fine grain structure and higher nanohardness, wear resistance and yield pressure compared to the as-cast counterpart. The combination of powder size reduction during ball milling and microstructural development during sintering resulted in improved properties. Therefore, the HBM+SPS processing approach shows promise for the manufacture of high hardness bulk TiAl alloys.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Soumya Ranjan Mishra, Li Ping Tan, Vikrant Trivedi, Manjusha Battabyal, P. S. Sankara Rama Krishnan, Durga Venkata Maheswar Repaka, Satyesh Kumar Yadav, Raju Vijayaraghavan Ramanujan, Budaraju Srinivasa Murty
Summary: The effect of doping on the thermoelectric properties of HH HEA Ti2NiCoSnSb was studied. Sb doping reduced thermal conductivity. Mass scattering by heavy (Ta, Zr) and light (Al) dopants was studied to further lower thermal conductivity. Zr-doped samples showed high HH phase content and low-lattice thermal conductivity of 1.9 W/(m·K). The poor solubility of Ta enhanced electrical properties. NiAl phase in Al-doped samples improved the power factor value significantly. A maximum ZT of 0.29 was achieved in all doped systems, with an optimum dopant level of Zr (25%), Ta (7.5%), and Al (10%).
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Shakti P. Padhy, Li Ping Tan, Vijaykumar B. Varma, V. Chaudhary, Z. Tsakadze, R. V. Ramanujan
Summary: This study developed a new high-throughput chemical synthesis method called hyper-heuristic combinatorial flow synthesis (HCFS). Using this method, a library of 91 Fe-Co-Ni powder compositions was successfully synthesized and their physical properties were evaluated using high-throughput screening and sintering methods. The study identified promising new Fe-Co-Ni compositions with multi-property optimization.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Richa Chaudhary, Varun Chaudhary, Raju Ramanujan, Terry W. J. Steele
Summary: The rheological behavior of polymer magnetic composites in the presence of an alternating magnetic field (AMF) was investigated using a custom-made magneto-rheometer. The study found that magnetoadhesive composites reached the gelation point quickly after AMF exposure and exhibited high shear modulus at low strains. The crosslinking kinetics were strongly influenced by factors such as nanoparticle loading, thermal conductivity, and initiation temperature. The study also determined the optimum process parameters for magnetic field processing of polymer magnetic composites using a high-throughput approach.
MATERIALS ADVANCES
(2022)
