Comparative study of magnetic and magnetotransport properties of Sm0.55Sr0.45MnO3 thin films grown on different substrates

Abstract

Highly oriented polycrystalline Sm0.55Sr0.45MnO3 thin films (thickness ∼100 nm) deposited on LaAlO3 (LAO, (001)), SrTiO3 (STO, (001)) and (La0.18Sr0.82) (Al0.59Ta0.41)O3 (LSAT, (001)) single crystal substrates by ultrasonic nebulized spray pyrolysis have been studied. The out of plane lattice parameter (OPLP) of the film on LAO is slightly larger than that of the corresponding bulk. In contrast, the OPLP of the films on STO and LSAT are slightly smaller than the corresponding bulk value. This suggests that the film on LAO is under compressive strain while LSAT and STO are under tensile strain. The films on LAO and LSAT show simultaneous paramagnetic-ferromagnetic (PM–FM) and insulator-metal transition (IMT) temperature at TC/TIM ∼ 165 K and 130 K, respectively. The PM–FM and IM transition occur at TC ∼ 120 K and TIM ∼ 105 K, respectively in the film on STO substrate. At T < TC, the zero field cooled–field cooled (ZFC–FC) magnetization of all the films shows strong bifurcation. This suggests the presence of a metamagnetic state akin to cluster glass formed due to coexisting FM and antiferromagnetic–charge order (AFM–CO) clusters. All the films show colossal magnetoresistance but its temperature and magnetic field dependence are drastically different. The films on LAO and STO show peak CMR around TC/TIM, while the film on LSAT shows MR > 99 % over a very wide temperature range of ∼40 K centred on TC/TIM. In the lower temperature region the magnetic field dependent isothermal resistivity also shows signature of metamagnetic transitions. The observed results have been explained in terms of the variation of the relative fractions of the coexisting FM and AFM–CO phases as a function of the substrate induced strain and oxygen vacancy induced quenched disorder

Nanopillar Spin Filter Tunnel Junctions with Manganite Barriers

“…At low temperatures, the MR curve shows hysteresis upon sweeping the magnetic field, which points towards the occurrence of a first order phase transition in the barrier layer. 39 With increasing magnetic field, the spins can be aligned easily but more energy is required average dimension of 500 nm x 500 nm were fabricated using focused ion beam (FIB) nanomachining technique described elsewhere. 40,41 Transport measurements were carried out in four-point configuration in a closed-cycle He cryostat system.…”

Rietveld refinement of X-ray powder diffraction data of Sm0.55Sr0.45MnO3 polycrystalline material

“…Perovskite manganites ( R MnO 3 , R —rare-earth element) have attracted the scientific community for the past decade due to their unusual magnetic and electric properties (Abdel-Latif, 2012). Manganites exhibiting colossal magnetoresistance have gained attention due to their wide applications in the field of spin electronics (Srivastava et al ., 2013). Among the various hole-doped rare-earth manganites, Sm 1− x Sr x MnO 3 (SSMO) is unique because this system exhibits colossal magnetoresistance (CMR) in a wide hole doping range from x = 0.3 to 0.52 with insulator metal transitions.…”

“…Among the various hole-doped rare-earth manganites, Sm 1− x Sr x MnO 3 (SSMO) is unique because this system exhibits colossal magnetoresistance (CMR) in a wide hole doping range from x = 0.3 to 0.52 with insulator metal transitions. For x = 0.3–0.52, the ground states are ferromagnetic metallic and become antiferromagnetic insulator for x > 0.52 (Srivastava et al ., 2013). Damay et al .…”

Strain modulated large magnetocaloric effect in Sm0.55Sr0.45MnO3 epitaxial films

“…The obtained lattice parameters match very well as reported by Srivastava et al on the same Sm 0.55 Sr 0.45 MnO 3 film. 13 These estimations imply that the film grown on LAO is in-plane compressively strained (a S_LAO ¼ 3.79 Å ). Smaller lattice constants (OPLP) of SSMO on STO (a S_STO ¼ 3.905 Å ) and LSAT (a S_LSAT ¼ 3.868 Å ) substrates could be attributed to the inplane tensile strain of the films.…”

“…Recently, Srivastava et al have also investigated the magnetic and magneto-transport properties of Sm 1Àx Sr x MnO 3 (x ¼ 0.45, 0.5) phase separated manganite films. 12,13 In our work, high quality epitaxial Sm 0.55 Sr 0.45 MnO 3 (SSMO) thin films have been fabricated on LaAlO 3 (LAO, (001)), SrTiO 3 (STO, (001)), and (La 0.18 Sr 0.82 )(Al 0.59 Ta 0.41 )O 3 (LSAT, (001)) single crystalline substrates by pulsed laser deposition (PLD) technique. This nanostructure would help to improve the performance of SSMO materials by exhibiting large tuneable magnetic entropy change and richer phase diagrams compared to bulk materials.…”