Strain-induced insulating ferromagnetism in LaMnO3 thin films from first-principles investigations

Ferromagnetic Enhancement in LaMnO3 Films with Release and Flexure

“…On the other hand, the enhancement of the ferromagnetism in LMO with out‐of‐plane lattice shrinking from releasing and bending, which is revealed by prior XRD analyses (Figure 1e) and is in accordance with the softening of out‐of‐phase stretching (B 3g ) mode in Raman spectra (Figure 2f), [ 26–28 ] is quite intriguing, comparing to the ferromagnetic suppression with the lattice shrinking reported in many previous studies. [ 12–18,29,30 ]…”

“…[ 38,39 ] Additionally, the octahedra of LMO we observed from STEM showed a magnified tilting, which was described by the intersection angle between adjacent octahedra (θ Mn1–O–Mn2 ) along c direction, after releasing and bending (Figure S8a, Supporting Information). This heavier tilting was responsible for the larger resistivity of LMO after releasing and bending, [ 29 ] as shown in Figure S8b, Supporting Information.…”

“…The underlying mechanism between the enhancement of the characteristic of P 2 1 / n symmetry and the enhancement of the ferromagnetism in LMO is schematically illustrated in Figure . Since the ferromagnetic interaction in ab plane is irrespective of the magnitude of distortion, [ 29,32 ] we focus on the ferromagnetic interaction along c direction. In the P 2 1 / n structure, the single e g electron of Mn1 (Mn2) occupies the d 3 z 2 – r 2 (d x 2 – y 2 ) orbital for lower energy.…”

“…On the other hand, the enhancement of the ferromagnetism in LMO with out-of-plane lattice shrinking from releasing and bending, which is revealed by prior XRD analyses (Figure 1e) and is in accordance with the softening of out-ofphase stretching (B 3g ) mode in Raman spectra (Figure 2f), [26][27][28] is quite intriguing, comparing to the ferromagnetic suppression with the lattice shrinking reported in many previous studies. [12][13][14][15][16][17][18]29,30] To identify how the magnetic properties depend on the LMO structure microscopically after releasing and bending, the atomic structure of the as-grown LMO, the FSLMO with K = 0 mm −1 , and that with K = 1 mm −1 were characterized with high-resolution spherical aberration-corrected STEM. Figure 3a shows the overview of the cross-section of the as-grown LMO under highangle annular dark-field (HAADF) mode and exhibits evident scarification of LMO, SAO, and STO with distinct contrasts.…”

Study on the decisive factor for metal–insulator transitions in a LaVO3 Mott–Hubbard insulator

“…20 This ambiguity mainly comes from the relatively scarce consideration of the various parameter candidates determining the electrical conduction mechanism compared to other correlated perovskite oxides. [18][19][20][21][22][23] Inspired by the fact that the B-O-B (B is a 3d metal) tilt angle between the corner shared octahedra in similar Ni and Mn-based perovskites have been reported to control the transport properties by tuning the hopping matrix elements, [22][23][24][25][26] the transport phenomena and its possible origin in undoped and doped lanthanum vanadate along with its structural and optical properties needs to be examined in detail. In this paper, two dopants, Ca 2+ and Sr 2+ of different ionic sizes were substituted in LaVO 3 and the origin of the difference in their transport behaviors is deeply investigated.…”