Standard enthalpies of formation of some 3d, 4d and 5d transition-metal stannides by direct synthesis calorimetry
摘要:
The standard enthalpies of formation of some 3d, 4d and 5d transition-metal stannides have been measured by high-temperature direct synthesis calorimetry at 1473+/-2 K. The following results are reported; all in kJ/mol of atoms: Ti(6)Sn(5): -(43.4+/-1.4); V(3)Sn: -(21.7+/-1.4); Zr(5)Sn(3): -(71.2+/-2.5); Nb(3)Sn: -(15.2+/-2.3); Ru(3)Sn(7): -(18.7+/-1.4); RhSn(2): -(42.1+/-2.4); Pd(3)Sn: -(57.8+/-1.9); Hf(5)Sn(3): -(49.2+/-2.1); Ir(5)Sn(7): -(15.0+/-1.9); IrSn(2): -(12.9+/-1.6); PtSn: -(58.8+/-2.3). The results are compared with some earlier values obtained by calorimetry or derived from emf or vapor-pressure measurements. They are also compared with predicted values from the semi-empirical model of Miedema et al., and with available enthalpies of formation for transition-metal germanides. (C) 1998 Elsevier Science B.V.