Abstract
We have used specific heat and neutron diffraction measurements on single crystals of for Fe concentrations to establish that chemical substitution of Ru with Fe acts as “chemical pressure” as previously proposed by Kanchanavatee et al. [Phys. Rev. B 84, 245122 (2011)] based on bulk measurements on polycrystalline samples. Notably, neutron diffraction reveals a sharp increase of the uranium magnetic moment at , reminiscent of the behavior at the “hidden order” to large-moment-antiferromagnetic phase transition observed at a pressure GPa in . Using the unit-cell volume determined from our measurements and an isothermal compressibility for , we determine the chemical pressure in as a function of . The resulting temperature –chemical pressure phase diagram for is in agreement with the established temperature –external pressure phase diagram of .
- Received 17 December 2014
- Revised 12 February 2015
DOI:https://doi.org/10.1103/PhysRevB.91.085122
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