Degradation of colossal magnetoresistance of europium hexaboride in the point contacts
Goyunov Yu.V.1
1FRC ”Kazan Scientific Center of RAS“, Kazan, Russia
Email: gorjunov@kfti.knc.ru
Point contacts fabricated of EuB6 semi-metal known for its colossal magnetoresistance at low temperatures were prepared. EuB6 is also featuring a very high melting temperature of (~2500 oC) and high hardness (~40 GPa/M) which depends on the crystallographic index. The geometry of the obtained point contacts is estimated and the temperature dependences of their magnetoresistance are measured, while monitoring the behavior of the magnetoresistance of a bulk sample. It is found that the temperature dependences of the magnetoresistance for bulk materials and point contacts are similar in terms of characteristic temperatures indicating the formation and ordering of spin polarons, and also have a similar temperature dependence of magnetization obtained after measurements of electron spin resonance. Yet, for the point contacts, the effective magneto-resistance values are significantly lower than their values for the same bulky material. The point contacts, in addition to the singularity near 15.5 K associated with the ferromagnetic ordering of magnetic polarons, also have a singularity near the temperature of 23 K. These findings are interpreted as a consequence of pinning of spin polarons inside the contacts at temperatures of 15.5 K and 23 K, which inhibits the shift of the magnetic interface boundaries when the contact size approaches the correlation length of the nematic magnetic phases in EuB6. Keywords: magnetic phase separation, colossal magnetoresistance, exchange interaction, spin polarons, quantum nematic.
- I.Ya. Korenblit, E.F. Shender. UFN, 126 (233), 1978 (in Russian)
- E.L. Nagaev. UFN, 166(833), 1996 (in Russian)
- M.Yu. Kagan, K.L. Kugel. UFN, 171 577 (2001) (in Russian)
- M.Yu. Kagan, A.V. Klaptsov, I.V. Brodsky, K.I. Kugel, A.O. Sboychakov, A.L. Rakhmanov. UFN, 173, (877) (2003) (in Russian)
- Stephanie A. Getty. Electron transport studies of the ferromagnetic semiconductor calcium hexaboride, a dissertation presented to the graduate school of the University of Florida in partial fulfillment of the requirements for the degree of doctor of philosophy, University of Florida, 2001, 136 pages
- M.A. Anisimov, A.V. Bogach, A.V. Kuznetsov, A.N. Azarevich, N.A. Samarin, S.V. Demishev, N.Yu. Shitsevalova, A.V. Dukhnenko, V.B. Filipov, N.E. Sluchanko, V.V. Glushkov. FTT, 61, 688(2019) (in Russian)
- V.A. Atsarkin, V.V. Demidov. ZhETF, 130, 677(2006) (in Russian)
- Chul-Hee Min, Boyoun Kang, Beong Ki Cho, En-Jin Cho, Byeong-Gyu Park. J. of the Korean Phys. Soc.,79, 734 (2021), doi:10.1007/s40042-021-00273-1
- M.J. Calderon, L.G.L. Wegener, P.B. Littlewood. Phys. Rev. B 70, 092408 (2004), doi: https://doi.org/10.1103/PhysRevB.70.092408
- M.L. Brooks, T. Lancaster, S.J. Blundell, W. Hayes, F.L. Pratt, Z. Fisk. Phys. Rev. B 70, 020401(R) (2004). doi: https://doi.org/10.1103/PhysRevB.70.020401
- Adham Amyan, Pintu Das, Jens Muller, Zachary Fisk. J. of the Korean Phys. Soc., 62, 1489 (2013). doi: 10.3938/jkps.62.1489
- A.F. Andreev, I.A. Grischuk. ZhETF, 87, 467 (1984) (in Russian)
- G. Beaudin, L.M. Fournier, A.D. Bianchi, M. Nicklas, M. Kenzelmann, M. Laver, W. Witczak-Krempa. Phys. Rev. B 105, 035104 (2022)
- E.V. Orlenko, F.E. Orlenko. FTT 58, 1338 (2016) (in Russian)
- O.A. Kosmachev. Scientific reports of Tavrida National University named after V.I. Vernadsky, Series "Fiziko-matematicheskiye nauki" 25, 64, 59 (2012) (in Russain)
- Ya.Yu. Matyunina, O.A. Kosmachev, Yu.A. Fridman. Fizika metallov i metallovedenie (in Russian) 125, 521 (2024) (in Russian)
- A.O. Sboychakov, K.I. Kugel, A.L. Rakhmanov. Phys. Rev. B 76, 195113 (2007)
- L.M. Falicov, J.C. Kimball. Phys. Rev. Lett. 22, 997 (1969)
- Tanmoy Mondal, Pinaki Majumdar., Phys. Rev. B 111, 195103 (2025), doi: https://doi.org/10.1103/PhysRevB.111.195103
- A.I. Akimenko, I.K. Janson. Pisma ZhETF |bf31, 209 (1980) (in Russian)
- Rajamallu Karre, Yidi Shen, Shuangxi Song, Yixuan Hu, Simanta Lahkar, Xiaodong Wang, Qi An, Kolan Madhav Reddy. Communications materials, 3, 24 (2022). https://doi.org/10.1038/s43246-022-00246-2
- Yu.V. Sharvin. ZhETF 48, 984-985 (1965) (in Russian)
- Yu.V. Goryunov, A.V. Levchenko. J. of Phys.: Conf. Series 391, 012014 (2012). doi:10.1088/1742-6596/391/1/012014
- T.S. Altshuler, Yu.V. Goryunov, N.Yu. Shitsevalova, A. Dukhnenko. J. of Phys.: Conf. Series 200, 032019 (2010). doi:10.1088/1742-6596/200/3/032019
- T.S. Altshuler, Yu.V. Goryunov, N.Yu. Shitsevalova, V.B. Filippov. Appl. Magn. Reson. 46, 25(2015). doi: 10.1007/s00723-014-0598-3
Подсчитывается количество просмотров абстрактов ("html" на диаграммах) и полных версий статей ("pdf"). Просмотры с одинаковых IP-адресов засчитываются, если происходят с интервалом не менее 2-х часов.
Дата начала обработки статистических данных - 27 января 2016 г.