In Situ X-Ray Nano-Imaging of Heterogeneous Structural Response in a Relaxor Ferroelectric

Magnetoelectric multiferroics transduce electrical and magnetic energy, which is critical for the development of new materials for sensors, motors, and computation devices. Composite heterostructures of a magnetostrictor coupled to a piezoelectric, such as the promising epitaxial FeGa on 0.7[PbMg_1/3Nb_2/3O₃] - 0.3[PbTiO₃] (PMN-PT), enable electric field control of magnetic polarization, while offering additional device utility compared to rare single-phase multiferroics. Such systems have been studied at the micron scale, but nanoscale strain distribution changes during switching are not well characterized. We use in situ hard x-ray nanodiffraction to simultaneously measure real and reciprocal space of devices under applied DC electric field, which allows us to attribute strain and lattice rotation information at the nanoscale. By applying non-linear least squares modeling of the phase coexistence across the morphotropic phase boundary in this multiferroic heteroepitaxial system, we correlate the local strain behavior in the direction of the applied field and along the domain polarization axes. We analyze the phase distribution as a function of electrical bias and demonstrate the potential for real-time analysis in advanced microelectronics characterization.