Partial ferroelastics

As it follows from the symmetry consideration of nonmagnetic crystals there are only I I possible nonferroelectric species for partial ferroelastics, which are characterized by the absence of full primary ferroic properties. It has been suggested that these partial ferroelastics should be full secondary ferroics (ferroelastoelectrics or/and ferrobielastics). To prove this statement the crystallophysical method was considered. It has been shown that partial ferroelastics may be (i) full ferrobielastic and full ferroelastoelectric (one species); (ii) full ferrobielastic only (two species); (iii) full ferroelastoelectric and partial ferrobielastic (the rest 8 species). primary and secondary ferroic properties of cristobalite (SiO2) and paratellurite (TeO2) crystals are discussed.