Nanoscale Probing of Magnetic and Electrical Properties of YIG/Si (100) Thin Films Grown by Pulsed Laser Deposition

Integration of yttrium iron garnet (YIG) with Si can bring new avenues for garnet-based complementary metal-oxide semiconductor compatible devices. Herein, investigations on the morphological, electrical, and magnetic properties of postgrowth annealed YIG thin films grown on Si substrate were systematically performed at nanoscale lateral resolution, employing the variants of atomic force microscopy (AFM) viz., conductive AFM (C-AFM), kelvin probe force microscopy, and magnetic force microscopy (MFM). Scanning electron microscopy analysis has revealed the formation of three different regions with varied crystallinity defined as center, dark, and surrounding matrix. Interestingly, AFM topography has not shown any surface variation of the obtained three different regions. Despite no variation in their surface topography, notable changes occur in their local conductivity, surface potential, and microstructure of their magnetic domains. C-AFM studies have shown the formation of conducting channels with three different resistivity regions. The tunneling current was enhanced nearly 50 times from the dark region (~1 pA) to the center region (~50 pA). MFM image analysis reveals the formation of two different magnetically active domains in the form of circles (-0.3°) distributed in a surrounding matrix (+0.3°) with a steep change in their magnetic phase degree. The formation of circular magnetic domains with highly distinguishable regions has suggested the potential of YIG/Si films for magnetic memory application. This work has shed light on the prospective of YIG/Si films for resistive and magnetic memory applications and fundamental aspects of growth of YIG on nongarnet substrates.