Impact of substrate on magnetic phase coexistence in bicritical Sm0.53Sr0.47MnO3 thin films

Abstract

Sm 0.53 Sr 0.47 MnO 3 thin films were deposited on single crystal LaAlO 3 (LAO/(001)) and SrTiO 3 (STO/(001)) substrates by DC magnetron sputtering. The -2 and -2 scans show that these films have very good crystallinity and the films on LAO and STO are under compressive and tensile strain, respectively. The films on LAO and STO substrates show ferromagnetic (insulator-metal) transition at T C~1 26 K (at T IM~1 28 K) and 120 K (T IM~1 17K), respectively.The magnetic state at T<T C is akin to cluster glass, which is formed by the presence of charge ordered-antiferromagnetic clusters in the ferromagnetic matrix. Huge drop in the resistivity at T IM and the associated hysteresis with respect to cooling and warming cycles reveal the bicritical and the first order nature of phase transition, which is also confirmed by the Banerjee criterion.The differences and similarities in the functional properties of films are explained in terms of substrate modified magnetic phase coexistence.

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

“…In case of the film on LAO the surface appeared to consist of large and big granules, while in case of the films on LSAT and STO substrates the granule size are more uniform. As compared to single crystalline Sm 0.53 Sr 0.47 MnO 3 thin films prepared by DC magnetron sputtering, 19,22 the surface roughness of these polycrystalline films is relatively higher. The representative surface topographs of films on LAO and STO are presented in Fig.…”

“…Recently, it has been shown that even a very small substrate induced strain could modify the magnetotransport properties in Sm 1-x Sr x MnO 3 (x ∼ 0.5) in the FMM regime (T < T C ). 19,22 In case of textured polycrystalline thin films the nature of the strain state is expected to be drastically different from the single crystalline and epitaxial thin films. In the textured/oriented polycrystalline thin film the local epitaxial regions are interrupted by the presence of GBs and around these regions the strain, irrespective of its nature (whether it is compressive or tensile) is expected to get relaxed.…”

“…1 3 thin films has been found to be rather difficult. [16][17][18][19] One of the factors that could supress the occurrence of PM-FM and IM transitions could be the extreme sensitivity of the magneto-electric phases (e.g., PMI, FMM and AFM-CO insulator (AFM-COI)) to the substrate induced strain in low W compounds. In small W compounds, (i) the reduced average RE-site cationic radius and hence smaller tolerance factor (t), (ii) the smaller Mn-O-Mn bond distance and the corresponding angle and (iii) enhanced size mismatch induced quenched disorder (σ 2 ) could lead to stronger sensitivity to the impact of substrate induced strain.…”

“…21 The impact of substrate induced strain on magnetic phase coexistence and consequent magnetotransport properties of small W material like Sm 1-x Sr x MnO 3 appears to be more dramatic. 19,22 In fact recently it has been shown that even a small strain can cause appreciable modifications in the magnetoelectric phase landscape of a low W manganite like Sm 1-x Sr x MnO 3 . 23 Recently we have studied Sm 0.55 Sr 0.45 MnO 3 (SSMO) thin films, wherein it was demonstrated that the substrate induced strain and oxygen vacancy ordering/disordering have significant impact on the magnetotransport properties.…”

Impact of strain on metamagnetic transitions in Sm0.5Sr0.5MnO3 thin films

“…Shorter annealing time resulted in poor characteristics. Here we would like to mention that annealing at 900 C has been used in case of various manganite thin films [18][19][20][21] and no interdiffusion at the substrate-film interface has been seen either in case of LAO or STO substrates. Annealing temperature higher than 900 C have also been used in several studies.…”