Strain-Induced Cluster Glass State in LaMnO₃ Films

Abstract

Strain effect has great influence on the magnetic properties of manganite films. Here, we report a new phenomenon in which the biaxial tensile strain can induce the formation of the cluster glass state in LaMnO3 (LMO) films. By comparing the properties of the LMO films grown on the LaAlO3, SrTiO3, and MgO substrates, the mechanism of the formation of the cluster glass state in LMO films was investigated in depth. We demonstrate that the formation of the cluster glass state in LMO films is due to the biaxial tensile strain, which leads to the competition between ferromagnetic and antiferromagnetic interactions by changing the percentage of Mn3+ and Mn4+ ions in the films. Our work demonstrates that strain is an important factor in the formation of the cluster glass state in manganite films.

Evidence for Spin Glass Transition in Hexagonal DyMnO3 without Substitutional Disorder

“…The best fit for eq to the M TRM ( t ) relaxation data is shown with continuous line in the same figure. It corresponds to M r = (1.2379 ± 0.0003) emu/g, M G = (0.0127 ± 0.0008) emu/g, n = (0.44 ± 0.02), and τ = (2312 ± 6) s. The value of exponent n is within the range 0 < n < 1 reported in the literature for SG systems − ,,,− which further supports the existence of the SG state in h-DyMnO 3 .…”

Ferromagnetic Enhancement in LaMnO3 Films with Release and Flexure

“…Since the valent state of Mn plays a significant role in manganite magnetism, [13,15,[23][24][25] we collected the unit-cell-resolved electron energy loss spectroscopy (EELS) spectra on Mn L edge within 10 u.c. region from the bottom of LMO layer of the as-grown LMO, the FSLMO with K = 0 mm −1 , and that with K = 1 mm −1 , as displayed in Figure S6a,b, Supporting Information, and Figure 2d, respectively.…”

“…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.…”

“…[13] However, the ferromagnetism in LMO is usually found to be restrained with out-of-plane lattice shrinking for films on the substrates. [14][15][16][17][18] Here, we report a novel and significant enhancement of the ferromagnetism of LMO films with releasing and bending, while the out-of-plane lattice was shrunk. High-resolution spherical aberration-corrected scanning transmission electron microscopy (STEM) and the firstprinciples calculations demonstrated that the enhancement of the ferromagnetism was attributed to the strengthening of the Mn-O-Mn super-exchange interactions caused by the more distinguished characteristics of the P2 1 /n structure with out-ofplane lattice shrinking after releasing and bending.…”