Magnetic properties and heat capacity of the three-dimensional frustrated S= 1/2 antiferromagnet PbCuTe2 O6
Journal
Physical Review B - Condensed Matter and Materials Physics
Journal Volume
90
Journal Issue
3
Pages
035141-1 - 035141-7
Date Issued
2014
Author(s)
Koteswararao, B.
Kumar, R.
Khuntia, P.
Bhowal, S.
Panda, S. K.
Rahman, M. R.
Mahajan, A. V.
Dasgupta, I.
Baenitz, M.
Kim, K. H.
Abstract
We report magnetic susceptibility (χ) and heat capacity (Cp) measurements along with ab initio electronic structure calculations on PbCuTe2O6, a compound made up of a three-dimensional (3D) network of corner-shared triangular units. The presence of antiferromagnetic interactions is inferred from a Curie-Weiss temperature (θCW) of about -22 K from the χ(T) data. The magnetic heat capacity Cm data show a broad maximum at Tmax≃1.15 K (i.e., Tmax/θCW≃0.05), which is analogous to the the observed broad maximum in the Cm/T data of a hyper-kagome system, Na4Ir3O8. In addition, Cm data exhibit a weak kink at T*≃0.87 K. While the Tmax is nearly unchanged, the T* is systematically suppressed in an increasing magnetic field (H) up to 80 kOe. For H≥80 kOe, the Cm data at low temperatures exhibit a characteristic power-law (Tα) behavior with an exponent α slightly less than 2. Hopping integrals obtained from the electronic structure calculations show the presence of strongly frustrated 3D spin interactions along with non-negligible unfrustrated couplings. Our results suggest that PbCuTe2O6 is a candidate material for realizing a 3D quantum spin liquid state at high magnetic fields. © 2014 American Physical Society.
SDGs
Publisher
American Physical Society
Type
journal article