Three-dimensional strain states and crystallographic domain structures of epitaxial colossal magnetoresistive La0.8Ca0.2MnO3 thin films

Abstract

Articles you may be interested inCurrent-sensitive electroresistance and the response to a magnetic field in La 0.8 Ca 0.2 MnO 3 epitaxial thin films J. Appl. Phys. 97, 10H706 (2005); 10.1063/1.1847092 Effects of film thickness and lattice mismatch on strain states and magnetic properties of La 0.8 Ca 0.2 MnO 3 thin filmsThe evolution of three-dimensional strain states and crystallographic domain structures of epitaxial colossal magnetoresistive La 0.8 Ca 0.2 MnO 3 films have been studied as a function of film thickness and lattice mismatch with two types of ͑001͒ substrates, SrTiO 3 and LaAlO 3 . In-plane and out-of-plane lattice parameters and strain states of the films were measured directly using normal and grazing incidence x-ray diffraction techniques. The unit cell volume of the films is not conserved, and it exhibits a substrate-dependent variation with film thickness. Films grown on SrTiO 3 substrates with thickness up to ϳ250 Å are strained coherently with a pure (001) T orientation normal to the surface. In contrast, films as thin as 100 Å grown on LaAlO 3 show partial relaxation with a (110) T texture. While thinner films have smoother surfaces and higher crystalline quality, strain relaxation in thicker films leads to mixed (001) T and (110) T textures, mosaic spread, and surface roughening. The magnetic and electrical transport properties, particularly Curie and peak resistivity temperatures, also show systematic variations with respect to film thickness.

Transmission electron microscopy study of epitaxial La0.8MnO3thin films on SrTiO3

“…Similar phenomenon has also been reported by Rao et al. [9] and Yang et al [16]. Compared with previous reports, the coexistence of three types of oriented domains of orthorhombic structure in La 0.8 MO 3 film with the substrate deposition temperature of 873K is rationalized due to the inherent pesudosymmetry of the structure and the 400nm film thickness.…”

“…[9][10][11][12][13] Transmission electron microscopy (TEM) is a powerful tool for characterization of microstructures in materials. In the past few years TEM has been widely applied in the studies of CMR materials, and particularly in thin films of external-doped lanthanum manganites [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28].…”

Correlation between structural parameters and the magnetocaloric effect in epitaxial La0.8Ca0.2MnO3/LaAlO3 thin film

“…The existence of domain structures in La 0.8 Ca 0.2 MnO 3 thin film has been previously reported. 42 To confirm the domain structure, we analyzed two adjacent columns by the nanobeam diffraction method. The beam size was 1.6 nm, so that the size was sufficient to acquire information from only one column.…”

Magnetic and transport properties of La0.8Sr0.2MnO3/La0.8Ca0.2MnO3 bilayer

“…This phenomenon becomes apparent in thin films. The lattice strain (and stress) accumulated during epitaxial growth of a film plays an important role in the formation of the spin-and the charge-ordered states, the metal-insulator transition temperature, and the value of magnetoresistance [2][3][4].…”

“…This phenomenon becomes apparent in thin films. The lattice strain (and stress) accumulated during epitaxial growth of a film plays an important role in the formation of the spin-and the charge-ordered states, the metal-insulator transition temperature, and the value of magnetoresistance [2][3][4].The effect of the kind of single-crystal substrate on the magnetic and the electronic properties of manganite films has been investigated well [5,6]. On the other hand, to develop hybrid devices based on multilayered CMR films detailed information on the mutual influence between constituent layers is required.…”