High Pressure Properties of a Ba-Cu-Zn-P Clathrate-I

Juli-Anna Dolyniuk; Kirill Kovnir

doi:10.3390/ma9080692

High Pressure Properties of a Ba-Cu-Zn-P Clathrate-I

Materials (Basel). 2016 Aug 12;9(8):692. doi: 10.3390/ma9080692.

Authors

Juli-Anna Dolyniuk¹, Kirill Kovnir²

Affiliations

¹ Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA. jdolyniuk@ucdavis.edu.
² Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA. kkovnir@ucdavis.edu.

Abstract

The high pressure properties of the novel tetrel-free clathrate, Ba₈Cu_13.1Zn_3.3P_29.6, were investigated using synchrotron powder X-ray diffraction. The pressure was applied using a diamond anvil cell. No structural transitions or decomposition were detected in the studied pressure range of 0.1-7 GPa. The calculated bulk modulus for Ba₈Cu_13.1Zn_3.3P_29.6 using a third-order Birch-Murnaghan equation of state is 65(6) GPa at 300 K. This bulk modulus is comparable to the bulk moduli of Ge- and Sn-based clathrates, like A₈Ga₁₆Ge₃₀ (A = Sr, Ba) and Sn_19.3Cu_4.7P₂₂I₈, but lower than those for the transition metal-containing silicon-based clathrates, Ba₈T_xSi_46-x, T = Ni, Cu; 3 ≤ x ≤ 5.

Keywords: bulk modulus; clathrate; high pressure; powder X-ray diffraction.