抄録
The ferroic state shifts higher by one order than the ferroelectric state shifts and the ferroelastic ones are considered. (Nonmagnetism is assumed.) The styles and directions of mechanical, electrical or combined forces effective on these second-order state shifts are expounded with simple examples. The orders of magnitude of the “coercive forces” for these state shifts are estimated. The optical discernibility between domains connected by such a state shift is discussed.