Open AccessМагнитные свойства слоистого кобальтита Sr-=SUB=-1-x-=/SUB=-Y-=SUB=-x-=/SUB=-CoO-=SUB=-3-delta-=/SUB=- (x = 0.1)
Author(s) -
И.О. Троянчук,
М. В. Бушинский,
Р.А. Лановский,
V. V. Sikolenko,
K. J. Ritter
Publication year - 2018
Publication title -
fizika tverdogo tela
Language(s) - English
Resource type - Journals
eISSN - 1726-7498
pISSN - 0367-3294
DOI - 10.21883/ftt.2018.10.46523.104
Subject(s) - tetragonal crystal system , monoclinic crystal system , superstructure , crystallography , perovskite (structure) , condensed matter physics , magnetoresistance , magnetization , materials science , antiferromagnetism , magnetic structure , phase (matter) , crystal structure , chemistry , magnetic field , physics , organic chemistry , quantum mechanics , thermodynamics
The structure, the magnetic and magnetotransport properties of perovskite Sr_0.9Y_0.1CoO_2.63 have been studied. The sample is shown to have a two-phase structure. The main phase has a tetragonally distorted unit cell and is described by space group I 4/ mmm . The broadening of the reflections with indices corresponding to doubling unit cell parameter c indicates the absence of the rigorous translation symmetry along axis c . The existence of the broadened superstructure reflection observed in the diffraction pattern at small angles at temperature lower than 400 K is explained by the existence of the monoclinic phase whose content is significantly lower than that of the tetragonal phase, but is dominant in the Sr_0.8Y_0.2CoO_3–δ composition. The spontaneous magnetization appears as the monoclinic phase forms. The magnetic structure is mainly G-type antiferromagnetic with magnetic moments 1.5μ_B in the layers of CoO_6 octahedra and 2μ_B in the anion-deficit CoO_4 + γ layers. The conduction of the Sr_0.9Y_0.1CoO_2.63 composition has a semiconducting character. The magnetoresistance is 57% in a field of 14 T at a temperature of 5 K and strongly decreases with the temperature increase.