Low-field magnetoresistance of La0.7Sr0.3MnO3 thin films with gradually changed texture

Abstract

A gradual change of the grain orientation with the substrate temperature (TS) during deposition has been observed for La0.7Sr0.3MnO3 films on Y-stabilized ZrO2(100) substrates. Epitaxial growth has been found around TS≈800 °C. Both the low-field and the high-field magnetoresistance (MR) observed for the ferromagnetic state of these polycrystalline colossal MR manganite films were found to systematically depend on the degree of texture. The experimental results suggest a crucial role of a highly resistive region at the grain boundaries for this MR effect.

Enhanced electro-magnetic properties in La0.7Sr0.3MnO3/ZrO2 composites

“…Hole-doped manganite perovskites of the type La 1-x Sr x MnO 3 , have attracted enormous interest in recent time due to the colossal magnetoresistance (CMR) effect [1][2][3]. Recently, enhanced low-field magnetoresistance (LFMR) or room temperature magnetoresistance (RTMR) properties have been successfully achieved for manganite composites by having grain boundaries material.…”

Low-Field Magnetoresistance in Manganite Thin Films

“…The influence of substrate temperature on the growth of LSMO thin films on YSZ substrates resulted in a gradual change of the grain orientation. Epitaxial growth has been found around Tsub = 800°C [6]. Table provides an overview of some characteristic parameters of representative films.…”

“…It was shown in our previous work [5,6] that the deposition temperature and mismatch of the lattice constants between the manganite film and the substrate have a crucial influence on the film growth. For a very low lattice mismatch the obtained films are single crystalline independent of employed deposition technique.…”

“…Refs. [5,6]). The substrates were monocrystalline plates (i) of Y-stabilised ZrO 2 (100) (YSZ) and (ii) of silicon buffered by YSZ layers.…”

“…It has been demonstrated that low-field magnetoresistance (LFMR) effects have an important influence in bulk polycrystalline materials [2,3], polycrystalline thin films [4][5][6], and thin films with reduced epitaxy [7,8]. It was established that the control of crystallinity perfection of thin manganite films, such as epitaxial strain or granularity, could be utilized for tuning of their MR properties, especially of LFMR [6][7][8]. In this paper, the influence of preparation conditions during magnetron sputtering (MS) or pulsed laser deposition (PLD) using various substrates on the resulting MR behaviour is investigated.…”