0 Growth pH Annealing temperature(°c) W8100 8.1 100 W8150 8.1 150 W8200 8.1 200 W9100 9 100 W9150 9 150 W9200 9 200 W10100 10 100 W10150 10 150 W10200 10 200

Table 1: Characterization of samples.