Epitaxial growth and strain of manganite thin films

Thin films of La1-xSrxMnO3 (x = 0.4) were fabricated using pulsed laser dep osition (PLD) method on various substrates for investigation of the effect of strain induced by lattice mismatch on the electro-magnetic properties. T he growth conditions were optimized on SrTiO3, substrate which has the best lattice matching (+ 0.9%) among the substrates used in this study. The res istivity and magnetization of thick films ( > 6 nm) on SrTiO3, were compara ble to those of bulk single crystals. With increasing the lattice mismatch by using LaAlO3, (-2.0%), the resistivity increased to show insulating beha vior caused by biaxial strain due to coherent epitaxial growth. However, fu rther increase of mismatch for NdAlO3, (-3.1%) and YAlO3, (-4.0%) made it p ossible to relax partly the strain, resulting in highly conductive films. ( C) 1998 Elsevier Science S.A. All rights reserved.