Article
Chemistry, Multidisciplinary
Lijuan Qian, Shiyu Zhou, Kang Wang, Gang Xiao
Summary: The study reveals that in a one-dimensional half-metallic CrO2 nanoscale conductor, the magnetoresistance induced by a single magnetic domain wall is enhanced by 70 fold when the channel width decreases from 200 nm to 30 nm, due to the increased domain wall resistance and additional contribution of ballistic magnetoresistance. The research predicts that a simple CrO2 nanowire impregnated with a constriction at a 150 nm(2) cross-section could achieve a magnetoresistance ratio of 100%, far exceeding that of a conventional ferromagnetic nanowire.
Article
Chemistry, Physical
Zhenhua Zhang, Ming Cheng, Zhiqiang Fan, Yong Liu, Dengjing Wang, Ke Wang, Rui Xiong, Zhihong Lu
Summary: This study found that the tunneling magnetoresistance (TMR) ratios of CrO2/XO2/CrO2 (X= Ti and Sn) magnetic tunnel junctions (MTJs) can reach up to the order of magnitude of 10(5)%, and the magnetoresistance (MR) ratio of CrO2/RuO2/CrO2 magnetic junctions (MJs) can reach the order of magnitude of 10(4)%. Epitaxial CrO2-based MTJs with TiO2 tunnel barriers of varying thickness were successfully fabricated. The highest MR ratio of 8.55% was observed for the CrO2/TiO2/Co2FeAl MTJ at 10K. However, the experimental MR ratios were lower than theoretical expectations, possibly due to the mixture of interface atoms and Cr magnetization reversal. The presence of oxygen vacancies in the TiO2 tunnel barrier also significantly weakened the TMR effect, while annealing treatment in an oxygen atmosphere increased the MR ratio of the CrO2/TiO2/Co2FeAl MTJ by about 33%, consistent with theoretical calculations.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Guozhao Zhang, Shouxin Cui, Haiwa Zhang, Zhenbao Feng, Guangyu Wang, Qinglin Wang, Yinwei Li, Cailong Liu
Summary: The magnetic properties and electrical transport behaviors of half-metallic ferromagnet CrO2 under high pressure were studied. The Hall coefficient, carrier concentration, and mobility showed discontinuous changes from 11.7 GPa to 14.9 GPa due to a structural transition. The resistivity decreased monotonically, attributed to the balance between decreased carrier concentration and increased carrier mobility.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Y. Fujita, Y. Miura, T. Sasaki, T. Nakatani, K. Hono, Y. Sakuraba
Summary: The study reveals a strong spin-scattering asymmetry at the interface of two ferromagnets, leading to enhanced MR output in pseudo-spin-valve devices at room temperature. The findings indicate the presence of large gamma at a half-metallic FM/FM interface and its impact on the CPP-GMR effect even at RT.
Article
Materials Science, Multidisciplinary
Zhao-Cai Wang, Lei Chen, Shuang-Shuang Li, Jing-Shi Ying, F. Tang, Guan-Yin Gao, Y. Fang, Weiyao Zhao, David Cortie, Xiaolin Wang, Ren-Kui Zheng
Summary: Linear magnetoresistance (LMR) is observed in half-metallic perovskite Sr2CrMoO6 thin films, with a maximum MR value exceeding +1600%, possibly due to high carrier density and ultrahigh mobility. This unusual behavior in ferrimagnetic double perovskite materials may broaden the applications of perovskites and stimulate research on metallic oxide ferri-/ferro-magnetic materials.
NPJ QUANTUM MATERIALS
(2021)
Article
Physics, Applied
Zixi Chen, Yuya Sakuraba, Yoshio Miura, Zehao Li, Taisuke Sasaki, Hirofumi Suto, Varun K. Kushwaha, Tomoya Nakatani, Seiji Mitani, Kazuhiro Hono
Summary: This study investigates the effects of off-stoichiometric compositional variations on the electronic structure of the Co2Fe(Ga0.5Ge0.5) full-Heusler alloy. First-principles calculations predict that Co-Fe defects introduce a finite density of states in the half-metallic gap, while Fe-Co defects preserve the gap but reduce spin polarization. Experimental results confirm that Ge-excess in Fe-excess CFGG enhances spin polarization. By adjusting the Fe and Ge compositions, the formation of secondary phases can be suppressed.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Y. V. Piskunov, A. F. Sadykov, V. V. Ogloblichev, A. G. Smolnikov, A. P. Gerashenko, P. Z. Si
Summary: In this study, Cr-53 NMR measurements were performed to investigate the static and dynamic properties of a half-metallic ferromagnet CrO2. Two magnetically nonequivalent Cr nuclei were observed in the ferromagnetic phase, despite all of the Cr ions being situated on the crystallographic equivalent sites. The temperature dependence of the Cr-53 spin-lattice relaxation rate was measured and it was found that the relaxation of nuclear magnetic moments is influenced by both orbital contribution and three-magnon processes.
Article
Nanoscience & Nanotechnology
Konstantin V. Larionov, Jose J. Pais Pereda, Songtian Li, Seiji Sakai, Pavel B. Sorokin
Summary: Integrating half-metallic materials and 2D spacers into vertical magnetoresistive spin valves may lead to effective low-power consumption storage and memory technologies. The study investigated magnetic tunnel junctions based on ferromagnetic CFGG Heusler alloy and MoS2 spacers of different thicknesses, demonstrating a large magnetoresistance value. The findings support the development of spintronics devices utilizing half-metallic Heusler alloys and diverse transition metal dichalcogenide family.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Multidisciplinary Sciences
S. Semboshi, R. Y. Umetsu, Y. Kawahito, H. Akai
Summary: HM-FCFMs are a special class of half-metals that exhibit zero magnetization at zero temperature. This study demonstrates the synthesis and observation of a compound with this characteristic, and highlights its importance in spintronics device applications.
SCIENTIFIC REPORTS
(2022)
Article
Crystallography
Hongxia Tian, Xiong Zhang, Abdullah Alodhayb, Feng Wang, Jie Jian, Jijie Huang
Summary: This study successfully fabricates vertically aligned nanocomposite thin films on flexible mica and investigates their properties and potential applications.
Article
Materials Science, Multidisciplinary
Hirokazu Fujiwara, Kensei Terashima, Junya Otsuki, Nayuta Takemori, Harald O. Jeschke, Takanori Wakita, Yuko Yano, Wataru Hosoda, Noriyuki Kataoka, Atsushi Teruya, Masashi Kakihana, Masato Hedo, Takao Nakama, Koichiro Yaji, Ayumi Harasawa, Kenta Kuroda, Shik Shin, Koji Horiba, Hiroshi Kumigashira, Yuji Muraoka, Takayoshi Yokoya, Yoshichika Onuki
Summary: The spin-dependent band structure of CoS2, a candidate for a half-metallic ferromagnet, was investigated to reevaluate its half-metallicity and electronic correlations. The results suggest that CoS2 is not a perfect half-metal but very close, with anomalously enhanced spin-dependent electron correlation effects near the half-metallic state.
Article
Physics, Applied
S. Das, R. G. Tanguturi, S. Ghosh, R. K. Dokala, R. Medwal, S. Gupta, Z. Yan, Y. Qi, R. S. Rawat, S. Thota
Summary: This study investigates the orientation dependent growth characteristics, electronic structure, transport, magnetic, and vibrational excitations of [La0.7Sr0.3MnO3/LaNiO3](10) superlattices on SrTiO3 substrates. The results reveal differences in electrical resistivity, ferromagnetism, and vibrational excitations among superlattices grown on different orientations.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Chemistry, Physical
Sheng Yu, Yu Wang, Yuzhen Song, Lei Xia, Xiaolong Yang, Hui Fang, Qiliang Li, Xiaoguang Li
Summary: Through hole doping, the CrI3 monolayer can achieve controlled magnetoresistance and enhanced spin polarization, providing new insights for the development of magnetic devices. Additionally, it has a significant impact on the stability of itinerant ferromagnetism and the enhancement of Curie temperature.
APPLIED SURFACE SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
R. Mahat, S. Kc, U. Karki, J. Y. Law, V Franco, I Galanakis, A. Gupta, P. LeClair
Summary: This paper presents a combined experimental and theoretical study on the properties of chromium-substituted Heusler alloys, showing great potential as half-metals with high spin polarization.
Article
Physics, Applied
Gui-fang Li, Yongqian Du, Tao You, Yue Tan, Gao-Qiang Li, Yun Zhang, Shibin Liu
Summary: Cubic half-metallic Heusler alloy Co2MnSi (CMS) thin films were successfully grown on Ge(111) substrates epitaxially with smooth and abrupt interfaces by inserting a hexagonal graphene inter-layer. X-ray diffraction measurement confirmed the L2(1) order for CMS thin films. The saturation magnetization (Ms) of CMS films annealed at 450 degrees C reached 891 emu/cm(3), which corresponds to 87% of the theoretically predicted value.
APPLIED PHYSICS LETTERS
(2022)