Ferromagnetic–antiferromagnetic transition and magnetotransport properties of La0.7Sr0.3Mn1−xNixO3 perovskites. (25th October 2017)

• Record Type: Journal Article
• Authors: Troyanchuk, I O; Karpinsky, D V; Tereshko, N V; Bushinsky, M V; Sikolenko, V V; Gavrilov, S A; Dubkov, S V; Silibin, M V
• Is Part Of: Materials research express. Volume 4:Number 10(2017)
• Publication Date: 2017-10-25
• Subjects: magnetoresistance -- magnetic interactions -- diffraction -- metal–insulator transition; Materials science -- Research -- Periodicals; Materials science -- Periodicals; 620.11
• DOI: 10.1088/2053-1591/aa8f85
• Languages: English
• ISSNs: 2053-1591

Abstract

Abstract: The crystal structure and magnetic properties of polycrystalline compounds La0.7 Sr0.3 Mn1− x Ni x O3 ( x ⩽ 0.37) were studied by neutron powder diffraction and magnetometry measurements, and the magnetotransport properties were also investigated, focusing on the magnetic state of the compounds. The crystal structure of the compounds remains rhombohedral upon chemical doping with Ni ions in the mentioned concentration range within the temperature interval 5–300 K. Doping with nickel ions causes a decrease in magnetization, and the Curie point drops from ~290 K for x = 0.1 compound down to ~70 K for x = 0.3 wherein the electrical resistivity of the compounds increases. The compounds with the dopant concentration x < 0.2 are characterized by pronounced magnetoresistance near the Curie points; the compounds with x ⩾ 0.2 show a gradual decrease in the magnetoresistance upon temperature increase. Neutron diffraction measurements of the compounds with x ⩾ 0.25 have showed a gradual reduction in ferromagnetic component, while an antiferromagnetic component of the G-type appears and progressively strengthens with an increase in the dopant concentration. The inhomogeneous magnetic state of the compounds with 0.25 < x ⩽ 0.3, attested by magnetization and neutron diffraction measurements, is governed by a competition between positive and negative exchange interactions formed between Ni and Mn ions depending on their oxidation state and electron configuration.