Chemical pressure tuning of URu2Si2 via isoelectronic substitution of Ru with Fe

• Published in: Physical review. B, Condensed matter and materials physics Condensed matter and materials physics, 2015-02, Vol.91 (8)
• Main Authors: Das, Pinaki, Kanchanavatee, N., Helton, J. S., Huang, K., Baumbach, R. E., Bauer, E. D., White, B. D., Burnett, V. W., Maple, M. B., Lynn, J. W., Janoschek, M.
• Format: Article
• Language: English
• Subjects: MATERIALS SCIENCE
• ISSN: 1098-0121; 1550-235X
• DOI: 10.1103/PhysRevB.91.085122

We have used specific heat and neutron diffraction measurements on single crystals of URu2–xFexSi₂ for Fe concentrations x ≤ 0.7 to establish that chemical substitution of Ru with Fe acts as “chemical pressure” Pch as previously proposed by Kanchanavatee et al. [Phys. Rev. B 84, 245122 (2011)] based on bulk measurements on polycrystalline samples. Neutron diffraction reveals a sharp increase of the uranium magnetic moment at x = 0.1, reminiscent of the behavior at the “hidden order” to large moment antiferromagnetic (LMAFM) phase transition observed at a pressure Px ≈ 0.5-0.7 GPa in URu₂Si₂. Using the unit cell volume determined from our measurements and an isothermal compressibility κT = 5.2×10⁻³ GPa⁻¹ for URu₂Si₂, we determine the chemical pressure Pch in URu2-xFexSi₂ as a function of x. The resulting temperature T-chemical pressure Pch phase diagram for URu2-xFexSi₂ is in agreement with the established temperature T-external pressure P phase diagram of URu₂Si₂.