Evidence of strong correlation and magnetotransport scaling in YbFe2As2

Abstract

Study of normal-state behaviour of YbFe2As2 single crystals has been reported through transport, specific heat and magnetotransport measurements. The YbFe2As2 crystals have been synthesized by using melt growth aided method. It is found that Sommerfeld coefficient (γ = 213.16 mJ mol−1K−1) is strongly enhanced suggesting existence of heavy quasiparticles. Analysis of resistivity data at low temperature yields Fermi-liquid co-efficient (A) value of 5.47 × 10−5 Ω cm K−2. Evaluation of Kadowaki-Woods ratio (A/γ2 = 1.204 × 10−5 μΩ cm mole2mJ−2) indicates that the YbFe2As2 crystal is a strongly correlated metal. The scaling analysis of magnetoresistance (MR) has been carried out. We have observed from MR results that YbFe2As2 show quadratic behaviour on magnetic field up to 5 T and beyond that it shows linear nature. Additionally, the verification of Kohler's rule has been explored. The measurement of MR as a function of magnetic field (B) up to 8 T indicates that Kohler's rule is not satisfied in YbFe2As2. However, it is found that YbFe2As2 satisfies an unusual scaling relationship between applied magnetic field and temperature within limited temperature range, which was reported in other iron-based superconductors recently.