Growth of α-Cr2O3 single crystals by mist CVD using ammonium dichromate

Ammonium dichromate and chromium chloride were examined via thermogravimetric and differential thermal analyses and used to grow α-Cr2O3 via mist chemical vapor deposition. Only the former resulted in noticeable film formation. Using ammonium dichromate, α-Cr2O3 single crystals were grown in a wide growth-temperature range of 300–440 °C. The dependences of the lattice constants a and c on the growth temperature and precursor concentration were explained by combination of (i) lattice reconstruction and (ii) unit-cell volume variation. A maximum growth rate of 10 nm/min; a low (0006) rocking-curve full width at half maximum of 150 arcsec; and low a and c lattice mismatches (with α-Ga2O3) of 0.7 and 1.4%, respectively, were achieved.