Martensitic transformation and large exchange bias in Mn-rich Ni–Mn–Sn thin films on mica substrates

Strain Control of Phase Transition and Exchange Bias in Flexible Heusler Alloy Thin Films

“…The thicknesses of the film and the Ti buffer layer are found to be about 130 and 20 nm, respectively, as determined from the SEM image. These results indicate that the Ti buffer layer has a significant contribution to the growth of high-quality films because of stress release, reduction of lattice mismatch, and good match of surface free energy between the Ni–Mn–Sn film and mica substrate. , The characterization of magnetic force microscopy (MFM) demonstrates that the Ni–Mn–Sn film has a stripe domain structure, and the domain width shows a significant increase in TS and CS states (Figure S6).…”

“…These results indicate that the Ti buffer layer has a significant contribution to the growth of high-quality films because of stress release, reduction of lattice mismatch, and good match of surface free energy between the Ni−Mn−Sn film and mica substrate. 13,49 The characterization of magnetic force microscopy (MFM) demonstrates that the Ni−Mn−Sn film has a stripe domain structure, 50 and the domain width shows a significant increase in TS and CS states (Figure S6). The thermomagnetic curves (M−T) for the films under zero field cooling (ZFC), field cooled cooling (FCC), and field cooled warming (FCW) modes in FS, TS, and CS states are shown in Figure 2a,c,e.…”

“…Heusler-type materials have distinctive structural and magnetic properties, underpinning modern technologies such as magnetic refrigeration, data storage, energy conversion, and so forth. − Recently, the metamagnetic Heusler alloys (MHAs) (Ni–Mn– X , X = In, Sn, Sb) have attracted growing interest, arising from their unique multifunctional properties, such as metamagnetic shape memory, large inverse magnetocaloric effect, ,− exchange bias (EB), − magnetic superelasticity, − and giant magnetoresistance effect. , These originate from the coupling between the magnetic/structural transitions and could be potentially used for applications in spintronics and magnetic devices . The performances of MHAs strongly depend on the magnetic and structural phase transitions, which determine their practical operating temperatures.…”

“…In this work, we report an efficient approach for bending strain control of magnetic phase transition and EB in MHA thin films on flexible substrates. Mn-rich Ni–Mn–Sn is chosen to be an ideal candidate because of its martensitic transformation near room temperature and complex magnetic states among different phase transitions, − which can be easily tailored by the external force. ,,− , By the application of both tensile (TS) and compressive strains (CM) (ε = 0.17% and ε = −0.18%) by bending the films in the radius of 3 mm (Figure S1), all characteristic temperatures can be significantly increased by about 10 K, which can effectively tune the operating temperature region of structural and magnetic transitions. In addition, EB is an important phenomenon and can be applied in spintronics, which can also be greatly enhanced, including EB field ( H E ), coercivity ( H C ), and blocking temperature ( T B ).…”

Preparation and Characterization of Orthorhombic AgMn Alloys by the Pulsed Laser Welding Technique

“…[ 14 ] In addition, martensitic transformation from the α to the γ phase of Al 2 O 3 was achieved upon rapid heating induced by pulsed laser irradiation. [ 15 ] It is mentioned that the high thermal stress caused by pulsed laser irradiation is the main driving force of the phase transformation in aluminum oxide. [ 15 ] The characteristics of these Al 2 O 3 nominated it for transformation toughening in ceramic materials.…”