Structural, Magnetic and Electrical Transport Properties of YIG Thin Films with Heavily Reduced Oxygen Content

Yttrium iron garnet (YIG) is very promising for spintronic devices due to its insulating nature, low damping and large magnon decay length. Moreover, YIG films have greatly facilitated the research on spin pumping, spin Seebeck effect and topological spintronics [1]. So far, many studies have shown that oxygen content is essential for tuning the structural and magnetic properties of YIG films [2]. But the effect was not so remarkable because only a small amount of oxygen content has been reduced.
We have investigated the effect of oxygen content on structural, magnetic and electrical transport properties of YIG films with heavily reduced oxygen contents, obtained via annealing with the presence of carbon. Both the saturation magnetic moment and lattice parameter of YIG decrease with reduced oxygen content, and the electrical resistivity of YIG decreases several orders of magnitude with the lowest value of 0.23 Ωcm at 300 K. The electronic transport behaviors are analyzed in detail by variable-range hopping (VRH) and trap-controlled space charge limited (SCL) conduction. This work is helpful for understanding the effect of oxygen content on the properties of YIG.

References
[1] A. V. Chumak, et. al, Nat. Phys. 11, 453 (2015)
[2] W. Noun, et. al. Phys. Rev. B. 81, 054411 (2010)