Maite Goiriena1,2,Zhuyun Xiao3,4,Rachel Steinhardt5,Victor Estrada3,Nobumichi Tamura4,Rajesh Chopdekar4,Alfredo García-Arribas2,Abdon Sepúlveda3,Darrell Schlom5,Rob Candler3,6,Jeffrey Bokor1,4
University of California, Berkeley1,University of the Basque Country2,University of California, Los Angeles3,Lawrence Berkeley National Laboratory4,Cornell University5,California NanoSystems Institute6
Maite Goiriena1,2,Zhuyun Xiao3,4,Rachel Steinhardt5,Victor Estrada3,Nobumichi Tamura4,Rajesh Chopdekar4,Alfredo García-Arribas2,Abdon Sepúlveda3,Darrell Schlom5,Rob Candler3,6,Jeffrey Bokor1,4
University of California, Berkeley1,University of the Basque Country2,University of California, Los Angeles3,Lawrence Berkeley National Laboratory4,Cornell University5,California NanoSystems Institute6
The magnetoelectric behavior of epitaxial Fe-Ga microstructures on top of (001)-oriented PMN-PT piezoelectric substrate is investigated under magnetic electron microscopy (XMCD-PEEM). Additionally, micron-scale strain distribution in PMN-PT is characterized by X-ray microdiffraction and examined with respect to the results of the Fe-Ga magnetoelectric switching. The magnetic reorientation is found to be strongly correlated with the size, shape and crystallographic orientation of the microstructures. In the case of square-shaped structures, size dictates the degree of influence of the strain distribution on both the initialization of the ground state and on the dynamics of the magnetic reorientation during application of voltage. On the other hand, the case of the elliptical microstructures demonstrates the importance of the orientation of the long axis with respect to the crystallographic directions of the PMN-PT, which leads to completely different magnetic responses. This study demonstrates that engineering highly magnetostrictive epitaxial microdevices is possible. It further elucidates that voltage-induced actuation can be largely tuned to achieve the desired type of magnetic switching ranging from vortex circulation reversal, domain wall motion, to a large rotation of magnetization. Because of the outstanding properties of the investigated material system, the reported findings are expected to be of great interest for the realization of next-generation energy-efficient magnetic memory, sensing and actuation devices.