ELASTIC PROPERTIES OF THE PSEUDOCUBIC PEROVSKITE (CSCD(NO2)3

Multidomain crystals of CsCd(NO2)3 grown from aqueous solutions at abo ut 310 K exhibit a quasi-cubic symmetry in their thermal expansion, el astic and thermoelastic properties. The elastic constants of the low-t emperature multidomain state resemble the behaviour of stable cubic pe rovskites almost quantitatively. This suggests that the trigonal low-t emperature phase of CsCd(NO2)3 possesses a quasi-cubic symmetry. The t ransition from the trigonal low-temperature phase into the cubic high- temperature phase at about 464 K is accompanied by a small deformation of about 10(-4) and a lambda-type variation of the thermal expansion.