Premium
Magnetically controlled space charge capacitance at La 1− x Sr x MnO 3 /Sr x La 1− x TiO 3 interfaces
Author(s) -
Schmidt Rainer,
GarcíaBarriocanal Javier,
Varela María,
GarcíaHernández Mar,
León Carlos,
Santamaría Jacobo
Publication year - 2016
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.201533036
Subject(s) - manganite , materials science , condensed matter physics , magnetocapacitance , strontium titanate , doping , capacitance , space charge , depletion region , heterojunction , dielectric spectroscopy , analytical chemistry (journal) , thin film , optoelectronics , ferroelectricity , nanotechnology , ferromagnetism , chemistry , semiconductor , physics , dielectric , electrode , multiferroics , quantum mechanics , electrochemistry , chromatography , electron
This work reports on magnetocapacitance (MC) effects in epitaxial heterostructures of nominally 15 unit cells (u.c.) LaMnO 3 (LMO) and 2 u.c. SrTiO 3 (STO) with an alternating layer‐repetition rate of 8: (LMO 15 /STO 2 ) 8 . Epitaxial multilayer growth at high temperatures (900 °C) activates a selective inter‐diffusion of La 3+ and Sr 2+ cations across the interfaces, which gives rise to Sr p‐doping of the LMO and La n‐doping of the STO layers. MC effects at the buried La 1– x Sr x MnO 3 /Sr x La 1– x TiO 3 (LSMO/SLTO) interfaces are probed by frequency, temperature and magnetic field dependent AC impedance spectroscopy. The technique is shown to be appropriate to account for the separate analysis of different resistance and capacitance contributions at the buried interfaces. As a result of the La/Sr inter‐diffusion process, Schottky barriers are formed at the LSMO/SLTO interfaces, which give rise to massive MC of up to ≈ −200% in the out‐of‐plane film direction. The capacitance of the manganite‐titanate LSMO/SLTO interfaces may be coupled indirectly to the resistance of the LSMO layers, because the Schottky space‐charge layers and their capacitance can be modulated by varying the concentration of highly mobile charge carriers in the LSMO with a magnetic field.