Pyroelectric Study on the Spontaneous Polarization in AgNa(NO2)2

Temperature dependence of the spontaneous polarization of ferroelectric AgNa(NO 2 ) 2 was measured by pyroelectric method in a temperature region of -150°C∼+40°C. The spontaneous polarization in the comply ordered state is estimated to be 9.85 µC cm -2 , corresponding to the dipole moment of 1.7 debye unit per a molecular dipole unit of (AgNa) 1/2 NO 2 . Estimation of the electrostrictive coefficients and the pressure coefficient of the Curie temperature is given, and the results are compared with those of NaNO 2 .