Crystal Growth of Cr2O3 Thin Films on YAlO3(001) Substrate

The Cr2O3 thin films are fabricated on YAlO3(YAO)(0 0 1) substrates etched with 5M and 12M NaOH solutions. After the etching with 12M NaOH solution, the YAO surface showed step-terraces structure with the step height of one unit. The surface morphology of Cr2O3 thin films grown on 5M, 12M etched YAO and r-cut sapphire substrate is almost similar even though the crystal structure of YAO is orthorhombic. Focusing on one grain of Cr2O3 thin film, the surface is two dimensionally flat with approximately unit step of 0.36nm. The Cr2O3 films expitaxially grow with the relationship of Cr2O3±[1 1 0] // YAO[1 0 0], Cr2O3±[1 1 1] // YAO[0 1 0], double-sign corresponds, and Cr2O3(1 1 0 2) // YAO(0 0 1).