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

The ferroelectricity of wurtzite, Sc x Ga1-x N (x = 0.35-0.44), was demonstrated in a metal-ferroelectric-metal capacitor. The remanent polarization (P (r)) obtained from positive-up negative-down measurements was high, exceeding 120 mu C cm(-2). The coercive field (E (c)) of Sc0.44Ga0.56N was approximately 3.6 MV cm(-1) at 300 K, which decreased to 3 MV cm(-1) at 473 K. We observed that regardless of the host material, the Sc concentration governed the E (c) value in Sc x Ga1-x N and Sc x Al1-x N, suggesting that the polarization switching started in the wurtzite unit cells containing Sc. Additionally, the E (c) of Sc x Ga1-x N was lower than that of Sc x Al1-x N when P (r) was equivalent.

Automated summary

The ferroelectricity of wurtzite ScxGa1-xN was demonstrated, with high remanent polarization and adjustable coercive field. The concentration of Sc governed the coercive field in ScxGa1-xN and ScxAl1-xN, suggesting the polarization switching started in wurtzite unit cells containing Sc.