Ferromagnetic cluster spin-glass behavior in PrRhSn(3)

We report the synthesis, structure, and magnetic and transport properties of a new ternary intermetallic compound PrRhSn(3), which crystallizes in LaRuSn(3)-type cubic structure (space group Pm (3) over barn). At low applied fields, the dc magnetic susceptibility exhibits a sharp anomaly below 6 K with an irreversible behavior in zero-field-cooled (ZFC) and field-cooled (FC) susceptibility below 5.5 K. The ac susceptibility exhibits a frequency-dependent anomaly, revealing a spin-glass behavior with a freezing temperature T(f) = 4.3 K. The observation of spin-glass behavior is further supported by a very slow decay of thermoremnant magnetization (mean relaxation time tau = 2149 s). However, a small jump at very low field in the isothermal magnetization at 2 K and a weak anomaly in the specific heat near 5.5 K reveal the presence of ferromagnetic clusters. The frequency dependence of the transition temperature T(f) in the ac susceptibility obeys the Vogel-Fulcher law nu = nu(0)exp[-E(a)/k(B)(T(f) -T(0))] with activation energy E(a)/k(B) = 19.1 K. This, together with an intermediate value of the parameter delta T(f) = Delta T(f)/T(f)Delta(log(10)nu) = 0.086, provides an evidence for the formation of a cluster glass state in PrRhSn(3). Further, we have analyzed the frequency dependence of transition temperature within the framework of critical slowing down, tau = tau(0)[(T(f) - T(SG))/T(SG))(-z nu)'], and found the characteristic time constant tau(0) = 2.04 x 10(-10) s and critical exponent z nu' = 10.9, which also support a cluster spin-glass behavior in this compound. The agnetic contribution of the specific heat reveals a broad Schottky-type anomaly centered around 10 K, and the analysis based on the crystal-electric-field model indicates a singlet ground state. Further, below Tf, the magnetic part of the specific heat exhibits a T(3/2) temperature dependence. The strong influence of the crystal electric field and a T(3/2) temperature dependence are also seen in the electrical resistivity, which reveals a metallic character and a high magnetoresistance. We also obtain a surprisingly large value of Sommerfeld-Wilson ratio R(W) approximate to 247.