A1 Refereed original research article in a scientific journal
Persistent photoinduced magnetization and oxygen non-stoichiometry in La0.9Ca0.1MnO3 films
Authors: Suominen T, Huhtinen H, Majumdar S, Paturi P, Zakhvalinskii VS, Laiho R
Publisher: IOP PUBLISHING LTD
Publication year: 2009
Journal:: Journal of Physics: Condensed Matter
Journal name in source: JOURNAL OF PHYSICS-CONDENSED MATTER
Journal acronym: J PHYS-CONDENS MAT
Volume: 21
Issue: 26
Number of pages: 8
ISSN: 0953-8984
DOI: https://doi.org/10.1088/0953-8984/21/26/266001
Abstract
The influence of thermal annealings on La0.9Ca0.1MnO3 (LCMO) films in oxygen and in vacuum with low hole doping is investigated in the phase separation region where competition between AFM and FM phases is high. Measurements by x-ray diffractometry, atomic force microscopy and magnetometry reveal changes in the lattice parameters and magnetic properties of the films, depending on the oxygen content. All films show magnetic cluster glass properties with similar freezing temperatures of around 45 K. Clearly the highest increase of the magnetization is observed in the films annealed in vacuum. We attribute this effect to trapping of unpaired electrons at oxygen vacancies where they can form rigid self-trapped magnetic polarons in potential wells of local moments. As a result long-range spin distortions with local ferromagnetic order may be realized. In conformity with these results, photoinduced persistent magnetization showing different mechanisms of generation, depending on the method of thermal annealing, is observed.
The influence of thermal annealings on La0.9Ca0.1MnO3 (LCMO) films in oxygen and in vacuum with low hole doping is investigated in the phase separation region where competition between AFM and FM phases is high. Measurements by x-ray diffractometry, atomic force microscopy and magnetometry reveal changes in the lattice parameters and magnetic properties of the films, depending on the oxygen content. All films show magnetic cluster glass properties with similar freezing temperatures of around 45 K. Clearly the highest increase of the magnetization is observed in the films annealed in vacuum. We attribute this effect to trapping of unpaired electrons at oxygen vacancies where they can form rigid self-trapped magnetic polarons in potential wells of local moments. As a result long-range spin distortions with local ferromagnetic order may be realized. In conformity with these results, photoinduced persistent magnetization showing different mechanisms of generation, depending on the method of thermal annealing, is observed.
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