TY - JOUR
T1 - Flux growth and physical properties of Mo3Sb7 single crystals
AU - Yan, J. Q.
AU - McGuire, M. A.
AU - May, A. F.
AU - Cao, H.
AU - Christianson, A. D.
AU - Mandrus, D. G.
AU - Sales, B. C.
PY - 2013/3/19
Y1 - 2013/3/19
N2 - Millimeter sized single crystals of Mo3Sb7 are grown using the self-flux technique and a thorough characterization of their structural, magnetic, thermal, and transport properties is reported. The structure parameters for the high-temperature cubic phase and the low-temperature tetragonal phase were determined with neutron single crystal diffraction. Both x-ray powder diffraction and neutron single crystal diffraction at room temperature confirmed that Mo3Sb7 crystallizes in Ir3Ge7-type cubic structure with space group Im 3̄m. The cubic-tetragonal structure transition at 53 K is verified by the peak splitting of (4 0 0) reflection observed by x-ray single crystal diffraction and the dramatic intensity change of the (12 0 0) peak observed by neutron single crystal diffraction. The structural transition is accompanied by a sharp drop in magnetic susceptibility, electrical resistivity, and thermopower while cooling. A weak lambda anomaly was also observed around 53 K in the temperature dependence of specific heat, and the entropy change across the transition is estimated to be 1.80 J/mol Mo K. The temperature dependence of magnetic susceptibility was measured up to 750 K, and it follows a Curie-Weiss behavior above room temperature. Analysis of the low-temperature magnetic susceptibility suggests a spin gap of 110 K around 53 K. A typical phonon thermal conductivity was observed in the low temperature tetragonal phase. A glassy phonon thermal conductivity above 53 K suggests a structural instability in a wide temperature range. Superconductivity was observed at 2.35 K in the as-grown crystals, and the dimensionless specific heat jump â-μC(T)/ γnTc was determined to be 1.49, which is slightly larger than the BCS value of 1.43 for the weak-coupling limit.
AB - Millimeter sized single crystals of Mo3Sb7 are grown using the self-flux technique and a thorough characterization of their structural, magnetic, thermal, and transport properties is reported. The structure parameters for the high-temperature cubic phase and the low-temperature tetragonal phase were determined with neutron single crystal diffraction. Both x-ray powder diffraction and neutron single crystal diffraction at room temperature confirmed that Mo3Sb7 crystallizes in Ir3Ge7-type cubic structure with space group Im 3̄m. The cubic-tetragonal structure transition at 53 K is verified by the peak splitting of (4 0 0) reflection observed by x-ray single crystal diffraction and the dramatic intensity change of the (12 0 0) peak observed by neutron single crystal diffraction. The structural transition is accompanied by a sharp drop in magnetic susceptibility, electrical resistivity, and thermopower while cooling. A weak lambda anomaly was also observed around 53 K in the temperature dependence of specific heat, and the entropy change across the transition is estimated to be 1.80 J/mol Mo K. The temperature dependence of magnetic susceptibility was measured up to 750 K, and it follows a Curie-Weiss behavior above room temperature. Analysis of the low-temperature magnetic susceptibility suggests a spin gap of 110 K around 53 K. A typical phonon thermal conductivity was observed in the low temperature tetragonal phase. A glassy phonon thermal conductivity above 53 K suggests a structural instability in a wide temperature range. Superconductivity was observed at 2.35 K in the as-grown crystals, and the dimensionless specific heat jump â-μC(T)/ γnTc was determined to be 1.49, which is slightly larger than the BCS value of 1.43 for the weak-coupling limit.
UR - http://www.scopus.com/inward/record.url?scp=84875336637&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.87.104515
DO - 10.1103/PhysRevB.87.104515
M3 - Article
AN - SCOPUS:84875336637
SN - 1098-0121
VL - 87
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 10
M1 - 104515
ER -