Ya. Boikov et al., Impact of granularity on transport properties of mechanically stressed La0.67Ca0.33MnO3 films, MAT SCI E B, 79(2), 2001, pp. 133-139
(La,Ca)MnO3 is one of so called collosal magnetoresistive materials and it
is of interest to correlate its transport properties to film growth in orde
r to optimize its performance. Two-hundred nanometers thick (100)La0.67Ca0.
33MnO3 films were grown by laser ablation on (100)SrTiO3, (100)LaAlO3 and (
100)(LaAlO3)(0.3) + (Sr2AlTaO6)(0.7) substrates. The films were granular in
structure with low angle boundaries between the grains. The volume of the
unit cell was considerably smaller for films grown on a SrTiO3 substrate th
an on LaAlO3. At temperatures higher than the one where the spins order, th
e strongest response of resistivity on temperature rho (T) was measured for
those (100)La0.67Ca0.33MnO3 films that had the smallest volume of the unit
cell. An increase of the lattice parameter for a film was accompanied by a
decrease of the resistivity. The films grown on (LaAlO3)(0.3) + (Sr2AlTaO6
)(0.7) substrates had the best crystallinity and the largest magnetoresista
nce. (C) 2001 Elsevier Science B.V. All rights reserved.