Fig. 1 shows the TG/DTA curves of the precipitates, which
were heated from 323 to 1473 K in static air at a heating rate of
10 K/min. The TG curve shows a minor weight loss from 323 to
381 K, followed by a major weight loss up to about 423 K,
another weight loss extending up to 518 K, and a small weight
loss up to 1273 K. Above 1273 K, there is no further weight loss
until 1473 K.