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Effect of magnetic field on the capacitance of the La 0.5 Ca 0.5 MnO 3 ‐based heterojunction
Author(s) -
Lu H. X.,
Sun J. R.,
Zhao J. L.,
Shen B. G.
Publication year - 2011
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201026481
Subject(s) - magnetocapacitance , heterojunction , materials science , condensed matter physics , capacitance , magnetic field , electrical impedance , ferroelectricity , optoelectronics , chemistry , dielectric , electrical engineering , physics , multiferroics , electrode , quantum mechanics , engineering
Effects of interface decoration and ac frequency, under which the impedance is measured, on the magnetoelectric property have been experimentally studied for the heterojunctions of La 0.5 Ca 0.5 MnO 3 /SrTiO 3 :Nb and La 0.5 Ca 0.5 MnO 3 /LaMnO 3 (3nm)/SrTiO 3 :Nb. It is found that the impedance of the junction can be well described by an effective circuit of two R – C sub‐circuits in series well above 100 K. Magnetocapacitance emerges and develops as temperature decreases, and shows a strong frequency‐dependent character. The maximal magnetocapacitance, under a field of 5 T, is ∼30 and ∼35% with and without the buffer layer, respectively. The incorporation of the LaMnO 3 layer shifts the upper temperature limit for significant magnetocapacitance from ∼120 to ∼200 K. Shrinkage of the depletion layer of the junction under magnetic field may be a main reason for the magnetoelectric effect observed here.