Resistivity of Manganite Thin Film Under Strain

Abstract

A complex study of the electron transport and magnetic characteristics of epitaxial manganite films La0.7Ba0.3MnO3 (LBMO) was carried out under conditions of the crystal structure tension caused by a mismatch between the parameters of the LBMO crystal and the substrate. The epitaxial thin films with the thickness 40-100 nm were grown by pulsed laser deposition at T = 700-800 °C in pure oxygen pressure 0.3-1 mbar. The substrates (110) NGO, (001) STO, (001) LAO, and (001) LSAT were used. By comparison of the lattice parameter of LBMO targets with substrate's one, the lattice mismatches were derived. We used substrates in which the lattice parameter was less than for the LBMO crystal one. It is shown that the temperature dependence of the film resistance in the low-temperature region does not depend on the film stress and is in good agreement with the calculation that takes into account the interaction of carriers with magnetic excitations in the presence of strongly correlated electron states. A nonmonotonic temperature dependence of the resistance of an LBMO film deposited on ferroelectric crystals PMN-PT that was observed. This feature is typical for manganites, and indicating the presence of ferromagnetism in the system was observed.

Conductivity of Manganite Films under the Action of Tension Caused by the Deformation of Substrate

“…The deformation of the PMN-PT substrate was measured on a strain gauge glued to the PMN-PT substrate [21], which give the relative deformation of the substrate. No absolute deformation of the substrate was measured.…”

“…Giant magnetostriction (up to 4 × 10 -4 ) was observed in a LBMO single crystal at a temperature close to Curie one [18]. The magnetic and resistive properties of epitaxial LBMO films are significantly changed during the growth on different substrates due to the deformation effect of a film lattice caused by substrate [19][20][21].…”

Ferroelectric-Ferromagnetic Heterostructures based on Sodium Substituted Lanthanum Manganite Thin films deposited on PMN-PT substrate by Pulsed Laser Deposition

“…Variation in thickness was also found to have a marked influence on other factors like nature of strain, lattice structure and ferroelectric polarization. There exist vast literature on strain induced domain structure of LaSrMnO 3 thin films grown on BTO substrates [14], magnetocaloric effects in La(0.7)Ca(0.3)MnO(3) thin films on BTO due to strain [15], reversible biaxial strain from substrate utilized to probe the response of magnetization to strain in SrRuO 3 films on PMN-PT[(1-x) Pb(Mg 1/3 Nb 2/3 )O 3 -xPbTiO 3 ] substrates [16], magnetization switching by electric field in heterostructures of nanomagnet Co and PMN-PT [17] and resistivity changes associated with strain in epitaxial La 0.7 Ba 0.3 MnO 3 thin films [18].…”

Strain Dependent Resistivity of Granular Manganite Systems: a Simple Quantitative Approach

“…In granular thin films, the externally applied strain no longer directly influences the crystal lattice, but it is generally incorporated by changing the grain arrangement. The scientific literature about the strain effects on the electrical transport properties of manganites is largely related to studies of epitaxial thin films [14][15][16] while the researches involving the effects on manganite granular films are more rare [17,18].…”