X線磁気円二色性分光を用いた金属磁性体の電界効果素子研究

摘要

Electric-field control of magnetic properties at room temperature has attracted much attention because of its great potential for enabling the construction of electric devices with ul- tra-low power consumption. Voltage-controlled magnetic anisotropy in ultrathin ferromagnetic metals could be the ultimate technology for the operation of spintronics devices, such as non-volatile random-access memory, where high-speed operation with high writing endurance is indispensable. This article reviews experimental studies to reveal the microscopic origin of the voltage effect. Specifically, two kinds of voltage effects are reviewed. One is correlated with ion migration. The other has a purely electronic origin, that is, electric-field-induced changes in the orbital magnetic moment and magnetic dipole Tz term, which can be characterized via X-ray magnetic circular dichroism spectroscopy.