Structure and Properties of Single Crystalline CaMg2Bi2, EuMg2Bi2, and YbMg2Bi2
- ORNL
Single crystals of CaMg{sub 2}Bi{sub 2}, EuMg{sub 2}Bi{sub 2}, and YbMg{sub 2}Bi{sub 2} were obtained from a Mg-Bi flux cooled to 650 C. These materials crystallize in the CaAl{sub 2}Si{sub 2} structure-type (P3{bar m}1, No. 164), and crystal structures are reported from refinements of single crystal and powder X-ray diffraction data. EuMg{sub 2}Bi{sub 2} displays an antiferromagnetic transition near 7 K, which is observed via electrical resistivity, magnetization, and specific heat capacity measurements. Magnetization measurements on YbMg{sub 2}Bi{sub 2} reveal a weak diamagnetic moment consistent with divalent Yb. Despite charge-balanced empirical formulas, all three compounds are p-type conductors with Hall carrier concentrations of 2.0(3) x 10{sup 19} cm{sup -3} for CaMg{sub 2}Bi{sub 2}, 1.7(1) x 10{sup 19} cm{sup -3} for EuMg{sub 2}Bi{sub 2}, and 4.6(7) x 10{sup 19} cm{sup -3} for YbMg{sub 2}Bi{sub 2}, which are independent of temperature to 5 K. The electrical resistivity decreases with decreasing temperature and the resistivity ratios {rho}(300 K)/{rho}(10 K) {le} 1.6 in all cases, indicating significant defect scattering.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Laboratory Directed Research and Development (LDRD) Program
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 1029951
- Journal Information:
- Inorganic Chemistry, Vol. 50, Issue 21; ISSN 0020-1669
- Country of Publication:
- United States
- Language:
- English
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