Thermally Induced Magnetoelastic Effect in Planar CoNi Microparticles on Lithium Niobate

The temperature effect on the magnetization distribution in planar CoNi microparticles deposited on hexagonal single-crystal lithium niobate has been studied. The transition of the magnetization distribution of such microparticles from multidomain to quasiuniform state by changing the substrate temperature has been demonstrated. It is established that the transition into the quasiuniform state occurs upon heating/cooling of the sample with respect to the deposition temperature of the microparticles. This is due to the noticeable difference in the thermal expansion coefficients along various crystallographic axes of lithium niobate. The uniaxial mechanical stresses are induced in the CoNi microparticles deposited on the crystal at the thermal change in the crystal size. The stresses induced in this manner are determined. In addition, this makes it possible to reduce the external magnetic field required for magnetization switching up to two times.