Thickness-dependent electronic structure modulation of ferromagnetic films on shape memory alloy substrates based on a pure strain effect

Pure strain-inducedelectronic structure modulation inferromagneticfilms is critical for developing reliable strain-assistedspintronic devices with low power consumption. For the conventional electricity-controlled strain engineering, it is difficult to reveal the pure straineffect onelectronic structure tunability due to the inseparability of pure straineffect and surface chargeeffect. Here, a non-electrically controlled NiTishape memoryalloy was utilized as a strain output substrate to induce a pure strain on attached Fefilms through a thermally controlledshape memory effect. The pure strain inducedelectronic structure evolution was revealed byin-situX-ray photoelectron spectroscopy and correlated with first-principles calculations andmagnetic anisotropy measurements. A compressive strain enhances the shieldingeffect for core electrons and significantly tunes their binding energy. Meanwhile, the strain modifies the partial density of states of outer d orbits, which may affect spin-orbit coupling strength and relatedmagnetic anisotropy. This work helps for clarifying the physical nature of the pure straineffect and developing the pure-strain-assistedspintronic devices.

Source: Applied Physics Letters - November 21, 2016 Category: Physics Authors: Chun Feng, Di Hu, Kui Gong, Xumin Jiang, Jianjuan Yin, Yi Cao, Xiao-Lei Tang, Feng Yang, Zhongfu Zhou, Guanghua Yu and D. Andrew Evans Source Type: research