Enhanced magnetization in epitaxial SrRuO3 thin films via substrate-induced strain

Abstract

Abstract:Epitaxial SrRuO 3 thin films were grown on SrTiO 3 , (LaAlO 3 ) 0.3 (SrAlO 3 ) 0.7 and LaAlO 3 substrates inducing different biaxial compressive strains. Coherently strained SrRuO 3 films exhibit enhanced magnetization compared to previously reported bulk and thin film values of 1.1-1.6 µ B per formula unit. A comparison of (001) and (110) SrRuO 3 films on each substrate indicates that films on (110) oriented have consistently higher saturated moments than corresponding (001) films. These observations indicate the importance of lattice distortions in controlling the magnetic ground state in this transitional metal oxide.

Evidence of high-spin Ru and universal magnetic anisotropy in SrRuO3thin films

“…[15][16][17][18] These experimental results, in which compressive strain enhanced the saturated moment, are at odds with theoretical studies where compressively strained (100) and (110) SRO films are predicted to have saturated magnetic moments suppressed from bulk values. 19 It is also predicted that an enhanced moment can be realized through the application of biaxial tension, although we are not aware of any experimental confirmation or contradiction of this prediction.…”

“…On LAO, films are difficult to grow fully strained; 40-50 nm thick films are partially relaxed and full relaxation occurs by 80 nm. 16 These fully relaxed films on LAO, as well as the thicker partially relaxed films on STO, can serve as important reference samples. If lattice distortions are controlling the film properties, these films should show much more bulk-like behavior.…”

Strain Effect in Epitaxial Oxide Heterostructures

“…LSAT, and (0 0 1) LaAlO 3 substrates), ρ decreases, which is consistent with the increase in the Ru─O─Ru bond angle, decrease in effective correlation, and increase in bandwidth (W) (Figure 12c) [85]. The slight increase in the ρ of films grown on (0 0 1) LaAlO 3 substrates is associated with either the rough surface quality of the films caused by the twin structure of (0 0 1) LaAlO 3 or the films being fully relaxed on this substrate (Figure 12d) [85].…”

“…The slight increase in the ρ of films grown on (0 0 1) LaAlO 3 substrates is associated with either the rough surface quality of the films caused by the twin structure of (0 0 1) LaAlO 3 or the films being fully relaxed on this substrate (Figure 12d) [85]. …”

“…Along with its electrode applications, due to its high metallicity upon ferromagnetic ordering, strain engineering of SrRuO 3 has become a popular research topic among thin-film scientists. Later, it has been found that the structural, metallic, and magnetic properties of SrRuO 3 thin films are highly sensitive to the substrate-induced strain (Figure 12a) [81][82][83][84][85][86][87][88][89][90][91][92].…”