Abstract
Synthesis and physico-chemical study of alluaudit material Na0,87Ca0,74Mn2,59(AsO4)(3) The title compound crystallizes in the monoclinic system C2/c. The parameters of the unit cell are: a=12.204(3) angstrom; b=12.968(3) angstrom; c=6.744(4) angstrom and beta=113.68(3)degrees. The anionic framework of the compound is built up by infinite layers linked together by Mn-As-O bridges to form a three-dimensional framework having two kinds of tunnels parallel to c-axis. The former contains the Na+ cations and the later the Ca2+ cations. Investigation of electrical properties of this compound by the complex impedance method showed that the material can be considered as a moderate ionic conductor.