Phase diagram and thermal expansion measurements on the system URu2-xFexSi2

Sheng Ran; Christian T Wolowiec; Inho Jeon; Naveen Pouse; Noravee Kanchanavatee; Benjamin D White; Kevin Huang; Dinesh Martien; Tyler DaPron; David Snow; Mark Williamsen; Stefano Spagna; Peter S Riseborough; M Brian Maple

doi:10.1073/pnas.1616542113

Phase diagram and thermal expansion measurements on the system URu2-xFexSi2

Proc Natl Acad Sci U S A. 2016 Nov 22;113(47):13348-13353. doi: 10.1073/pnas.1616542113. Epub 2016 Nov 8.

Authors

Sheng Ran^{1

2}, Christian T Wolowiec^{1

2}, Inho Jeon^{2

3}, Naveen Pouse^{1

2}, Noravee Kanchanavatee^{1

2}, Benjamin D White^{1

2}, Kevin Huang^{2

3}, Dinesh Martien⁴, Tyler DaPron⁴, David Snow⁴, Mark Williamsen⁴, Stefano Spagna⁴, Peter S Riseborough⁵, M Brian Maple^{6

2

3}

Affiliations

¹ Department of Physics, University of California, San Diego, La Jolla, CA 92093.
² Center for Advanced Nanoscience, University of California, San Diego, La Jolla, CA 92093.
³ Materials Science and Engineering Program, University of California, San Diego, La Jolla, CA 92093.
⁴ Quantum Design, Inc., San Diego, CA 92121.
⁵ Physics Department, Temple University, Philadelphia, PA.
⁶ Department of Physics, University of California, San Diego, La Jolla, CA 92093; mbmaple@ucsd.edu.

Abstract

Thermal expansion, electrical resistivity, magnetization, and specific heat measurements were performed on URu_2-xFe_xSi₂ single crystals for various values of Fe concentration x in both the hidden-order (HO) and large-moment antiferromagnetic (LMAFM) regions of the phase diagram. Our results show that the paramagnetic (PM) to HO and LMAFM phase transitions are manifested differently in the thermal expansion coefficient. The uniaxial pressure derivatives of the HO/LMAFM transition temperature T₀ change dramatically when crossing from the HO to the LMAFM phase. The energy gap also changes consistently when crossing the phase boundary. In addition, for Fe concentrations at x_c ≈ 0.1, we observe two features in the thermal expansion upon cooling, one that appears to be associated with the transition from the PM to the HO phase and another one at lower temperature that may be due to the transition from the HO to the LMAFM phase.

Keywords: URu2Si2; hidden order; thermal expansion.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.