ESR investigation of the spin dynamics in (Gd1−xYx)2PdSi3

Abstract We report electron-spin resonance (ESR) measurements in polycrystalline samples of (Gd1−xYx)2PdSi3. We observe the onset of a broadening of the linewidth and of a decrease of the resonance field at approximately twice the Neel temperature in the paramagnetic state. This characteristic temperature coincides with the electrical resistivity minimum. The high-temperature behavior of the linewidth is governed by a strong bottleneck effect.