Abstract

The quaternary alloy (CuIn)(2)NbTe5 was synthesized by solid-state reaction using the melt and annealing technique. The thermal analysis shows that this compound melts at 1026 K. The present alloy is isotypic with Cu2FeIn2Se5 and crystallizes in the space group P (4) over bar 2c (N degrees 112), with unit cell parameters a = 6.1964(2) angstrom, c = 12.4761(4) angstrom, c/a = 2.01, V = 479.02(3) angstrom(3). (CuIn)(2)NbTe5, belonging to the system (CuInSe2)(1)(-x)(FeSe)(x) with x = 1/3, is a new adamantane compound with a P-chalcopyrite structure. This structure is characterized by a double alternation of anions-cations layers according to the Te-Te: Nb-In-Nb-In: Cu-In-Cu-In: Te-Te sequence, along the 010 direction.