STRUCTURAL PHASE TRANSITIONS IN CO(II) AND NI(II) DIPHOSPHATES IN THE TEMPERATURE RANGE 290-1000 K

Abstract This paper presents a study of the temperature dependence of the dielectric permittivity, electric resistivity and magnetic susceptibility of the diphosphate M 2 P 2 O 7 , where M = Co ( II ) and Ni ( II ). The study, which was carried out in the temperature range 290–1000 K, indicated that both compounds sustain three phase transitions each. The existing literature offers a description of one phase transition for both compounds (α → β).