Single crystals of the R-type ferrite SrNiRu5O11 were grown from a chloride flux. The hexagonal crystal structure contains ruthenium located on distorted kagome nets. The low-temperature dc magnetic susceptibilities (χ and χ, perpendicular and parallel to the c axis, respectively) diverge as T-0.3, and do not exhibit any indication of long-range magnetic order down to 4.5 K. The electrical resistivity varies as T1.6 below 40 K, which is typical of non-Fermi liquids, and may originate from a competition between residual magnetic interactions among Ni2+ (S=1) spins and geometrical frustration on the two-dimensional kagome lattice of Ru3+ (S=) spins. The transverse magnetoresistivity ρxy at constant temperature T=5K for current (J) -magnetic field (H) configurations, JHc axis and JHc axis, reveals no anomalous contribution, which is consistent with the absence of magnetic order. Fits of the specific heat data below 10 K require a dominant, but unusual electronic term of the form Cel=γT1.2, which is expected for massless Dirac fermion states in topological insulators, or spin-liquid phases.
|Journal||Physical Review B|
|State||Published - Jan 30 2017|
Bibliographical noteFunding Information:
We thank Ingrid Werner for performing the microprobe measurements and Dr. Shiyu Zhang for experimental support. We thank R. K. Kremer for heat capacity measurements. Research at the University of Kentucky was supported by the U.S. Department of Energy Grant No. DE-FG02-97ER45653.
© 2017 American Physical Society.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics