V. Motalov, A. M. Dunaev, A. O. Tsybert
Jun 1, 2017
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Influential Citations
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Journal
International Journal of Mass Spectrometry
Abstract
Abstract The sublimation of solid gadolinium and thulium triiodides was studied by Knudsen effusion mass spectrometry. The partial vapor pressures [atm] of the monomer and dimer molecules were determined as: ln p (GdI 3 ) = −(32.31 ± 0.18) × 10 3 / T + (21.38 ± 0.21) for 777–946 K; ln p (Gd 2 I 6 ) = −(38.07 ± 0.42) × 10 3 / T + (24.49 ± 0.47) for 843–946 K; ln p (TmI 3 ) = −(31.84 ± 0.25) × 10 3 / T + (21.88 ± 0.29) for 760–965 K; and ln p (Tm 2 I 6 ) = −(38.23 ± 0.27) × 10 3 / T + (25.71 ± 0.43) for 799–965 K. In addition, the trimers Gd 3 I 9 and Tm 3 I 9 were detected in very small fractions. On the basis of a joint analysis of all available data in literature, the sublimation enthalpies [kJ mol −1 ] at 298.15 K are recommended as 283 ± 9 (GdI 3 ), 336 ± 16 (Gd 2 I 6 ), 366 ± 50 (Gd 3 I 9 ), 276 ± 3 (TmI 3 ), 330 ± 6 (Tm 2 I 6 ), and 354 ± 50 (Tm 3 I 9 ). The standard formation enthalpies [kJ mol −1 ] of the gaseous species at 298.15 K are −341 ± 9 (GdI 3 ), −912 ± 16 (Gd 2 I 6 ), −1506 ± 50 (Gd 3 I 9 ), −344 ± 5 (TmI 3 ), −909 ± 7 (Tm 2 I 6 ), and −1506 ± 50 (Tm 3 I 9 ).