Magnetic phase transformations and magnetotransport phenomena in La{sub 0.7}Sr{sub 0.3}Mn{sub 1–} {sub x}Co{sub x}O{sub 3} perovskite compounds

Journal Article · Tue Aug 15 04:00:00 EDT 2017 · Journal of Experimental and Theoretical Physics

DOI:https://doi.org/10.1134/S1063776117070238· OSTI ID:22756364

Bushinsky, M. V.; Karpinsky, D. V. ^[1]; Sikolenko, V. V. ^[2]; Chobot, A. N.; Tereshko, N. V.; Mantytskaya, O. S. ^[1]; Schorr, S. ^[3]

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1. National Academy of Sciences of Belarus, Scientific and Practical Materials Research Center (Belarus)
2. Joint Institute for Nuclear Research (Russian Federation)
3. Helmholtz-Zentrum Berlin (Germany)

The compositions La{sub 0.7}Sr{sub 0.3}Mn{sub 1–} {sub x}Co{sub x}O{sub 3} (0.13 ≤ x ≤ 1) are studied by neutron diffraction, magnetometry, and measuring the magnetotransport properties. The substitution of cobalt ions for manganese ions is shown to decrease the magnetization and the Curie temperature from 270 K (x = 0.13) to 140 K (x = 0.33). As the cobalt ion content increases to x = 0.5, the Curie temperature increases to 190 K, the magnetization decreases, and the electrical resistivity increases. At x > 0.5, the temperature of transition into a paramagnetic state decreases to 68 K (x = 0.8) and then again increases to 225 K for the La{sub 0.7}Sr{sub 0.3}CoO{sub 3} composition. The magnetoresistive effect in the range 0.3 ≤ x ≤ 0.4 reaches 97% and decreases gradually with increasing temperature without anomalies near the Curie point. At x ≤ 0.2, the magnetoresistive effect increases near the Curie temperature. The composition at x = 0.6 is stoichiometric, and no coherent magnetic contribution to neutron scattering is detected. The magnetic properties near x ∼ 0.5 are assumed to be caused by partial ordering of Co{sup 3+} and Mn{sup 4+} ions, and the Co{sup 3+} ions can be in both low- and high-spin states. The magnetic interaction between Co{sup 3+} ions in a high-spin state and Mn{sup 4+} is predominantly ferromagnetic, and the ferromagnetic part of the exchange interactions is close to the ferromagnetic part. These data are used to plot a magnetic La{sub 0.7}Sr{sub 0.3}Mn{sub 1–} {sub x}Co{sub x}O{sub 3} phase diagram.

• OSTI ID: 22756364
• Journal Information: Journal of Experimental and Theoretical Physics, Journal Name: Journal of Experimental and Theoretical Physics Journal Issue: 2 Vol. 125; ISSN JTPHES; ISSN 1063-7761
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COBALT IONS
CURIE POINT
EXCHANGE INTERACTIONS
HIGH SPIN STATES
MAGNETIC PROPERTIES
MAGNETIZATION
MANGANESE IONS
MATRICES
NEUTRON DIFFRACTION
OZONE
PHASE DIAGRAMS
PHASE TRANSFORMATIONS