Crystal Structure and Properties of the Titanium Stannide Ti₂Sn₃

Abstract

The recently reported binary stannide Ti 2 Sn 3 is confirmed. Its structure was determined from single-crystal X-ray diffractometer data: Cmca, a = 596.7(4), b = 1995(2), c = 701.3(4) pm , Z = 8, R = 0.027 for 817 structure factors and 30 variable parameters. The crystal structure is compared to that of V 2 GaSn 2 , which has the same space group symmetry and atomic positions. The Ga atoms of V 2 GaSn 2 occupy those Sn positions of Ti 2 Sn 3 which have the smaller coordination number. The two different titanium atoms of Ti 2 Sn 3 have 11 neighbors of which 3 and 4, respectively, are titanium atoms. The three different tin atoms have 5 titanium with 8 or 10 additional tin neighbors. They show only a slightly broadened but unresolved 119 Sn Mössbauer signal with an isomer shift reflecting the high tin content of this intermetallic compound and a relatively large quadrupole splitting of 2.10 mm·s -1 . Ti 2 Sn 3 is a good metallic conductor and a Pauli paramagnet.