Electronic properties of a heavy-fermion U(Ru0.92Rh0.08)2Si2 single cr

Abstract

We report the crystal structure and highly anisotropic magnetic, transport, and thermal properties of an exceptionally good single crystal of U(Ru 0.92 Rh 0.08 ) 2 Si 2 , prepared using a modified Czochralski method. Our study, that also includes neutron diffraction results, shows all the heavy-fermion signatures of pristine URu 2 Si 2 ; however, the superconductivity, hidden order, and remnant weak antiferromagnetic orders are absent. Instead, the ground state of the doped system can be classified as a spin liquid that preserves the heavy-fermion character. U(Ru 0.92 Rh 0.08 ) 2 Si 2 exhibits a short-range magnetic order distinguished by reflections of a Lorentzian profile at q III = ( ) positions that disappear above ∼15 K. The short-range order seems to be a precursor of a long-range magnetic order that occurs with higher Rh concentration. We indicate that these short-range fluctuations involve, at least partially, inelastic scattering processes.

Magnetic structure in a U(Ru0.92Rh0.08)2Si2 single crystal studied by neutron diff

“…1), to establish the lattice constants and orientation matrix of the crystal with respect to the laboratory system and to evaluate the magnetic moment magnitudes. We found that the intensities recorded in zero field agree well after necessary absorption and extinction corrections with the crystal structure parameters determined previously [13].…”

“…The system does not order magnetically, so only short-range order (SRO) characterized by Q 3 at low temperatures is detected [13]. For fields up to 58 T applied along the a axis (not shown) the magnetization is tiny and increases linearly with field.…”

“…While in the former system it is a spin-density wave (SDW) characterized by Q 1 = (0.600), suspected to be of multi-Q nature [11], in the latter case the propagation vector is Q 2 = ( 2 3 00). However, these experiments suffer from a reduced signal-to-noise ratio because of the pulsed field nature of the magnetic field, and an inability to survey a large portion of the reciprocal space during a single field pulse due the use of a triple-axis spectrometer that prevents the detector from being tilted out of the scattering plane.Here, we report results achieved at the recently completed HFM-EXED facility at Helmholtz-Zentrum Berlin (HZB) that enables neutron studies in static fields up to 26 T-a study of the field-induced magnetic phase in U(Ru 0.92 Rh 0.08 ) 2 Si 2 , in which we deliberately suppressed HO and allowed for shortrange magnetic order.The details of our U(Ru 0.92 Rh 0.08 ) 2 Si 2 single-crystal preparation, quality, and other physical properties are presented elsewhere [13]. For the present neutron studies, a 4 × 4 × 4 mm 3 single crystal was cut using spark erosion to have edges along the principal axes and glued onto a copper holder, which was placed in a cryostat capable of reaching 1.4 K. This was inserted into a high-field magnet HFM-a hybrid solenoid (13 T, 4 MW resistive insert, and series-connected 13 T superconducting outsert) [14,15].…”

“…The details of our U(Ru 0.92 Rh 0.08 ) 2 Si 2 single-crystal preparation, quality, and other physical properties are presented elsewhere [13]. For the present neutron studies, a 4 × 4 × 4 mm 3 single crystal was cut using spark erosion to have edges along the principal axes and glued onto a copper holder, which was placed in a cryostat capable of reaching 1.4 K. This was inserted into a high-field magnet HFM-a hybrid solenoid (13 T, 4 MW resistive insert, and series-connected 13 T superconducting outsert) [14,15].…”

“…The magnetic signal was detected using compensated pickup coils and scaled to match values obtained in static fields up to 14 T [13].…”