Lower ferroelectric coercive field of ScGaN with equivalent remanent polarization as ScAlN.

The ferroelectricity of wurtzite, Sc _x Ga_{1âˆ' x} N (x  = 0.35â€"0.44), was demonstrated in a metalâ€"ferroelectricâ€"metal capacitor. The remanent polarization (P _r) obtained from positive-up negative-down measurements was high, exceeding 120 ÎĽ C cm^âˆ'2. The coercive field (E _c) of Sc_0.44Ga_0.56N was approximately 3.6 MV cm^âˆ'1 at 300 K, which decreased to 3 MV cm^âˆ'1 at 473 K. We observed that regardless of the host material, the Sc concentration governed the E _c value in Sc _x Ga_{1âˆ' x} N and Sc _x Al_{1âˆ' x} N, suggesting that the polarization switching started in the wurtzite unit cells containing Sc. Additionally, the E _c of Sc _x Ga_{1âˆ' x} N was lower than that of Sc _x Al_{1âˆ' x} N when P _r was equivalent. [ABSTRACT FROM AUTHOR]