A1 Refereed original research article in a scientific journal
Mechanisms of photoinduced magnetization in Pr0.6Ca0.4MnO3 studied above and below charge-ordering transition temperature
Authors: Elovaara T, Tikkanen J, Granroth S, Majumdar S, Felix R, Huhtinen H, Paturi P
Publisher: IOP PUBLISHING LTD
Publication year: 2017
Journal: Journal of Physics: Condensed Matter
Journal name in source: JOURNAL OF PHYSICS-CONDENSED MATTER
Journal acronym: J PHYS-CONDENS MAT
Article number: ARTN 425802
Volume: 29
Issue: 42
Number of pages: 8
ISSN: 0953-8984
eISSN: 1361-648X
DOI: https://doi.org/10.1088/1361-648X/aa847b
Abstract
We report the effect of photonic field on the electronic and magnetic structure of a low bandwidth manganite Pr0.6Ca0.4MnO3 (PCMO) thin film. In particular, the present study confirmed a mechanism that was recently proposed to explain how optical excitation can bias or directly activate the metamagnetic transition associated with the colossal magnetoresistance (CMR) effect of PCMO. The transition is characterized by a shift in the dynamic equilibrium between ferromagnetic (FM) and antiferromagnetic clusters, explaining how it can be suddenly triggered by a sufficient external magnetic field. The film was always found to support some population of FM-clusters, the proportional size of which could be adjusted by the magnetic field and, especially in the vicinity of a thermomagnetic irreversibility, by optical excitation. The double exchange mechanism couples the magnetic degrees of freedom of manganites to their electronic structure, which is further coupled to the ion lattice via the Jahn-Teller mechanism. In accordance, it was found that producing optical phonons into the lattice could lower the free energy of the FM phase enough to significantly bias the CMR effect.
We report the effect of photonic field on the electronic and magnetic structure of a low bandwidth manganite Pr0.6Ca0.4MnO3 (PCMO) thin film. In particular, the present study confirmed a mechanism that was recently proposed to explain how optical excitation can bias or directly activate the metamagnetic transition associated with the colossal magnetoresistance (CMR) effect of PCMO. The transition is characterized by a shift in the dynamic equilibrium between ferromagnetic (FM) and antiferromagnetic clusters, explaining how it can be suddenly triggered by a sufficient external magnetic field. The film was always found to support some population of FM-clusters, the proportional size of which could be adjusted by the magnetic field and, especially in the vicinity of a thermomagnetic irreversibility, by optical excitation. The double exchange mechanism couples the magnetic degrees of freedom of manganites to their electronic structure, which is further coupled to the ion lattice via the Jahn-Teller mechanism. In accordance, it was found that producing optical phonons into the lattice could lower the free energy of the FM phase enough to significantly bias the CMR effect.
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