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arXiv · 1706.08433

LaCu$_{6-x}$Ag$_{x}$: A promising host of an elastic quantum critical point

L. Poudel·C. de la Cruz·M. R. Koehler·M. A. McGuire·V. Keppens·D. Mandrus·A. D. Christianson
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Abstract

Structural properties of LaCu$_{6-x}$Ag$_{x}$ have been investigated using neutron and x-ray diffraction, and resonant ultrasound spectroscopy (RUS) measurements. Diffraction measurements indicate a continuous structural transition from orthorhombic ($Pnma$) to monoclinic ($P2_1/c$) structure. RUS measurements show softening of natural frequencies at the structural transition, consistent with the elastic nature of the structural ground state. The structural transition temperatures in LaCu$_{6-x}$Ag$_{x}$ decrease with Ag composition until the monoclinic phase is completely suppressed at $x_c$ = 0.225. All of the evidence is consistent with the presence of an elastic quantum critical point in LaCu$_{6-x}$Ag$_{x}$.

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L. Poudel, C. de la Cruz, M. R. Koehler, M. A. McGuire, V. Keppens, D. Mandrus, A. D. Christianson. 2017-06-26. LaCu$_{6-x}$Ag$_{x}$: A promising host of an elastic quantum critical point. https://doi.org/10.1016/j.physb.2017.08.066

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