Ferroelastic Strain Induced Antiferroelectric‐Ferroelectric Phase Transformation in Multilayer Thin Film Structures

Abstract

Coupling effects among mechanical, electrical and magnetic parameters in thin fi lm structures including ferroic thin fi lms provide exciting opportunity for creating device functionalities. For thin fi lms deposited on a substrate, their mechanical stress and microstructure are usually determined by the composition and processing of the fi lms and the lattice and thermal mismatch with the substrate. Here it is found that the stress and structure of an antiferroelectric (Pb 0.97 ,La 0.02 )(Zr 0.90 ,Sn 0.05 ,Ti 0.05 )O 3 (PLZST) thin fi lm are changed completely by a ferroelastic strain in a magnetic shape memory (MSM) alloy Ni-Mn-Ga (NMG) thin fi lm on the top of the PLZST, despite the existence of the substrate constraint. The ferroelastic strain in the NMG fi lm results in antiferroelectric (AFE) to ferroelectric (FE) phase transformation in the PLZST layer underneath. This fi nding indicates a different strategy to modulate the structure and function for multilayer thin fi lms and to create unprecedented devices with ferroic thin fi lms.

Thermal strain induced large electrocaloric effect of relaxor thin film on LaNiO3/Pt composite electrode with the coexistence of nanoscale antiferroelectric and ferroelectric phases in a broad temperature range

“…Accordingly, the AFE phases (see the double P-E loops in Fig. 5a), 5c) and 5e) will be well kept since the in-plane tensile stress is helpful to stabilize them in the PLZST thin films [46]. It should be noted that the residual stress also depends on the film orientation due to the anisotropic thermal expansion of the PLZST thin film [44].…”

Enhancement of energy storage in epitaxial PbZrO3 antiferroelectric films using strain engineering

“…12,13 However, recent studies argued compressive strain could stabilize a FE phase in (001) pc -epitaxial PbZrO 3 thin films 14 and multilayer PZST films. 15 Recent theory calculations have suggested that AFE phase stability with strain is also related to the growth orientation of AFE films 16 and has been proven by experimental results from highly oriented polycrystalline PbZrO 3 films. 17 Previous studies, however, have focused on how AFE-FE phase transition and related polarization switching are affected by strain.…”

Critical role of the coupling between the octahedral rotation andA-site ionic displacements inPbZrO3-based antiferroelectric materials investigated byin situneutron diffraction

“…Antiferroelectric (AFE) materials such as PbZrO 3 (PZO) and PZO-based materials exhibit many distinctive and useful properties, such as large electric-field (E-field) -induced strains, double-polarization-electric-field (P-E) hysteresis loops, and thermal/mechanical depolarization. These distinctive properties have many possible applications and have already led to the development of various devices, including potential generators, energy storage devices, and sensors [1][2][3][4][5][6][7]. The origin of these useful properties is associated with the distinctive structural transition between the AFE and FE phases induced by external stimuli such as E-field, mechanical force, and temperature [5,[8][9][10][11].…”

“…A symmetry mode decomposition [19,20] of, for example, Corker et al's structure refinement [21] shows that the ground state of PZO is dominated by two large-amplitude primary modes. The first mode is associated with the modulation wave vector q 1 = [1/4,1/4,0] p (of 2 symmetry) and results in antiparallel displacements of A-site Pb 2+ and the neighboring apical O 2− ions along the resultant a, or [1][2][3][4][5][6][7][8][9][10] p , directions [of magnitudes 0.277 and 0.215Å, respectively; see Fig. 1(a)].…”