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Title: Mictomagnetic State in an EuBaCo{sub 2–x}O{sub 5.5–δ} Single Crystal

Abstract

The magnetic properties of an EuBaCo{sub 1.9}O{sub 5.36} single crystal are studied in the temperature range T = 2–300 K and the magnetic field range H ≤ 90 kOe. This binary layered cobaltite single crystal has vacancies in the cobalt and oxygen sublattices, in contrast to the stoichiometric EuBaCo{sub 2}O{sub 5.5} composition. All cobalt ions in EuBaCo1.9O5.36 are in a trivalent state. The single crystal has an orthorhombic structure with space group Pmmm, and its unit cell parameters are a = 3.883 Å, b = 7.833 Å, and c = 7.551 Å. The field and temperature dependences of the magnetization of the single crystal demonstrate that it is ferrimagnet below T{sub C} = 242 K. At T < 300 K, all three spin states of the Co{sup 3+} ions are present. The nearest-neighbor interactions give antiferromagnetic (AFM) and ferromagnetic (FM) contributions to the exchange energy. The ratio of the AFM to the FM contributions changes when temperature decreases because of a change in the spin state of the Co{sup 3+} ions. The single crystal exhibits signs of mictomagnetism at low temperatures in high magnetic fields. At T = 2 K and H = 90 kOe, the zero-field and nonzero-field magnetizationsmore » are strongly different because of a uniaxial magnetic anisotropy, which tends to set magnetization along the magnetic field applied in cooling throughout the crystal volume. As a result, a complex ferrimagnetic structure with a noncollinear direction of Co{sup 3+} spins appears. The following phenomena characteristic of mictomagnets are also observed in the EuBaCo{sub 1.9}O{sub 5.36} single crystal: a shift in a magnetization hysteresis loop when temperature decreases, retained hysteretic phenomena and no magnetization saturation in high magnetic fields, and an orientation transition. The mictomagnetic state in EuBaCo{sub 1.9}O{sub 5.36} is shown to be caused by the structural distortions induced by vacancies in the cobalt and oxygen sublattices and by the frustration of AFM and FM exchange interactions.« less

Authors:
; ; ;  [1]
  1. Russian Academy of Sciences, Institute of Metal Physics, Ural Branch (Russian Federation)
Publication Date:
OSTI Identifier:
22749855
Resource Type:
Journal Article
Journal Name:
Journal of Experimental and Theoretical Physics
Additional Journal Information:
Journal Volume: 126; Journal Issue: 5; Other Information: Copyright (c) 2018 Pleiades Publishing, Inc.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1063-7761
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ATOMIC FORCE MICROSCOPY; COBALT IONS; EXCHANGE INTERACTIONS; LAYERS; MAGNETIC FIELDS; MAGNETIC PROPERTIES; MAGNETIZATION; MICTOMAGNETISM; MONOCRYSTALS; ORTHORHOMBIC LATTICES; SPACE GROUPS; SPIN; TEMPERATURE DEPENDENCE

Citation Formats

Arbuzova, T. I., Naumov, S. V., E-mail: naumov@imp.uran.ru, Telegin, S. V., and Korolev, A. V. Mictomagnetic State in an EuBaCo{sub 2–x}O{sub 5.5–δ} Single Crystal. United States: N. p., 2018. Web. doi:10.1134/S1063776118040015.
Arbuzova, T. I., Naumov, S. V., E-mail: naumov@imp.uran.ru, Telegin, S. V., & Korolev, A. V. Mictomagnetic State in an EuBaCo{sub 2–x}O{sub 5.5–δ} Single Crystal. United States. doi:10.1134/S1063776118040015.
Arbuzova, T. I., Naumov, S. V., E-mail: naumov@imp.uran.ru, Telegin, S. V., and Korolev, A. V. Tue . "Mictomagnetic State in an EuBaCo{sub 2–x}O{sub 5.5–δ} Single Crystal". United States. doi:10.1134/S1063776118040015.
@article{osti_22749855,
title = {Mictomagnetic State in an EuBaCo{sub 2–x}O{sub 5.5–δ} Single Crystal},
author = {Arbuzova, T. I. and Naumov, S. V., E-mail: naumov@imp.uran.ru and Telegin, S. V. and Korolev, A. V.},
abstractNote = {The magnetic properties of an EuBaCo{sub 1.9}O{sub 5.36} single crystal are studied in the temperature range T = 2–300 K and the magnetic field range H ≤ 90 kOe. This binary layered cobaltite single crystal has vacancies in the cobalt and oxygen sublattices, in contrast to the stoichiometric EuBaCo{sub 2}O{sub 5.5} composition. All cobalt ions in EuBaCo1.9O5.36 are in a trivalent state. The single crystal has an orthorhombic structure with space group Pmmm, and its unit cell parameters are a = 3.883 Å, b = 7.833 Å, and c = 7.551 Å. The field and temperature dependences of the magnetization of the single crystal demonstrate that it is ferrimagnet below T{sub C} = 242 K. At T < 300 K, all three spin states of the Co{sup 3+} ions are present. The nearest-neighbor interactions give antiferromagnetic (AFM) and ferromagnetic (FM) contributions to the exchange energy. The ratio of the AFM to the FM contributions changes when temperature decreases because of a change in the spin state of the Co{sup 3+} ions. The single crystal exhibits signs of mictomagnetism at low temperatures in high magnetic fields. At T = 2 K and H = 90 kOe, the zero-field and nonzero-field magnetizations are strongly different because of a uniaxial magnetic anisotropy, which tends to set magnetization along the magnetic field applied in cooling throughout the crystal volume. As a result, a complex ferrimagnetic structure with a noncollinear direction of Co{sup 3+} spins appears. The following phenomena characteristic of mictomagnets are also observed in the EuBaCo{sub 1.9}O{sub 5.36} single crystal: a shift in a magnetization hysteresis loop when temperature decreases, retained hysteretic phenomena and no magnetization saturation in high magnetic fields, and an orientation transition. The mictomagnetic state in EuBaCo{sub 1.9}O{sub 5.36} is shown to be caused by the structural distortions induced by vacancies in the cobalt and oxygen sublattices and by the frustration of AFM and FM exchange interactions.},
doi = {10.1134/S1063776118040015},
journal = {Journal of Experimental and Theoretical Physics},
issn = {1063-7761},
number = 5,
volume = 126,
place = {United States},
year = {2018},
month = {5}
}