Systematic control of stress-induced anisotropy in pseudomorphic iron garnet thin films

Large-Pore Mesoporous Ho3Fe5O12 Thin Films with a Strong Room-Temperature Perpendicular Magnetic Anisotropy by Sol–Gel Processing

“…64,65 The PIB 107 -b-PEO 150 -templated HoIG thin films show this magnetization-reversal transition at comparably small applied fields in the out-of-plane direction, thereby suggesting that the easy axis for magnetic alignment is not likely to lie parallel to the substrate plane, as often observed for sub-micrometer-thick films due to shape anisotropy. 37 A similar observation has been made by Kalashnikova et al for 10 μm-thick epitaxially grown films. 66 They found nearly square shaped out-of-plane hysteresis loops in the vicinity of T comp and explained this result by growthinduced anisotropy.…”

“…Given that HoIG has negative λ 111 and λ 100 magnetostriction constants, 53 such lattice distortions force the easy axis for magnetic alignment (along the [111] crystallographic direction in garnets) to lie perpendicular to the tension direction, as reported for strained epitaxial garnet thin films. 37 We presume that the preference for magnetization in the out-of-plane direction stems from a similar strain anisotropy that overcomes the strong shape anisotropy of the thin films. However, in contrast to epitaxially grown layers, this orientation effect is independent of the substrate used, because the "mechanical stress" does not result from a lattice or thermal expansion mismatch between the substrate and the film.…”

High-quality single-crystal thulium iron garnet films with perpendicular magnetic anisotropy by off-axis sputtering

“…The optimized films had the room-temperature saturation magnetization (M s ) of 99 emu/cm 3 (RT bulk value: 110 emu/cm 3 ) with an H c of 2.4 Oe, which was the lowest value ever reported for TmIG films. [7][8][9][10]12 TmIG films with low coercive field require low current induced effective field to switch the magnetization so that the current density of magnetization switching can be reduced. Fig.…”

“…Interestingly, thulium iron garnet (TmIG) films grown on (111)-oriented gadolinium gallium garnet (GGG) substrates were reported to show stress-induced PMA. 7,8 The PMA was originated from magnetization-lattice coupling under sufficient tensile strain, and overcomes the shape anisotropy, owing to the large magnetostriction constant of TmIG. Anomalous Hall effect was observed in TI/TmIG heterostructure up to a temperature as high as 400K, 9 making TI/TmIG a very promising candidate for realization of QAHE at elevated temperature.…”

“…These can be applied to data storage, magnetic random access memory, logic/memory utilizing domain wall. 10 Most reported TmIG films have been grown by pulsed laser deposition (PLD), [7][8][9][10]12 which is known to deposit thin films in a limited small area. Using magnetron sputtering to grow TmIG thin films is preferred because sputtering has been widely used in larger scale applications.…”