Magnetic state of the structural separated anion-deficient La{sub 0.70}Sr{sub 0.30}MnO{sub 2.85} manganite

Journal Article · Tue Nov 15 00:00:00 EST 2011 · Journal of Experimental and Theoretical Physics

DOI:https://doi.org/10.1134/S1063776111130127· OSTI ID:22027982

Trukhanov, A V ^[1]; Vasiliev, A N ^[2]; Balagurov, A M ^[3]; Szymczak, H ^[4]

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1. Scientific Practical Materials Research Centre of NAS of Belarus (Belarus)
2. Moscow State University (Russian Federation)
3. Joint Institute for Nuclear Research (Russian Federation)
4. Institute of Physics, PAS (Poland)

The results of neutron diffraction studies of the La{sub 0.70}Sr{sub 0.30}MnO{sub 2.85} compound and its behavior in an external magnetic field are stated. It is established that in the 4-300 K temperature range, two structural perovskite phases coexist in the sample, which differ in symmetry (groups R3-bar c and I4/mcm). The reason for the phase separation is the clustering of oxygen vacancies. The temperature (4-300 K) and field (0-140 kOe) dependences of the specific magnetic moment are measured. It is found that in zero external field, the magnetic state of La{sub 0.70}Sr{sub 0.30}MnO{sub 2.85} is a cluster spin glass, which is the result of frustration of Mn{sup 3+}-O-Mn{sup 3+} exchange interactions. An increase in external magnetic field up to 10 kOe leads to fragmentation of ferromagnetic clusters and then to an increase in the degree of polarization of local spins of manganese and the emergence of long-range ferromagnetic order. With increasing magnetic field up to 140 kOe, the magnetic ordering temperature reaches 160 K. The causes of the structural and magnetic phase separation of this composition and formation mechanism of its spin-glass magnetic state are analyzed.

• OSTI ID: 22027982
• Journal Information: Journal of Experimental and Theoretical Physics, Vol. 113, Issue 5; Other Information: Copyright (c) 2011 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7761
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANIONS
EXCHANGE INTERACTIONS
LANTHANUM COMPOUNDS
MAGNETIC FIELDS
MAGNETIC MOMENTS
MAGNETIZATION
MANGANATES
MANGANESE
MANGANESE IONS
NEUTRON DIFFRACTION
OXYGEN
POLARIZATION
SPIN
SPIN GLASS STATE
STRONTIUM COMPOUNDS
TEMPERATURE DEPENDENCE
TETRAGONAL LATTICES
TRIGONAL LATTICES
VACANCIES