Huge First-Order Metamagnetic Transition in the Paramagnetic Heavy-Fermion System CeTiGe

We report on the observation of large, step-like anomalies in the magnetization (\(\Delta M = 0.74\)\,\(\mu_{\rm B}\)/Ce), in the magnetostriction (\(\Delta l/l_{0} = 2.0 \cdot 10^{-3}\)), and in the magnetoresistance in polycrystals of the paramagnetic heavy-fermion system CeTiGe at a critical magnetic field \(\mu_0 H_c \approx \) 12.5\,T at low temperatures. The size of these anomalies is much larger than those reported for the prototypical heavy-fermion metamagnet CeRu\(_2\)Si\(_2\). Furthermore, hysteresis between increasing and decreasing field data indicate a real thermodynamic, first-order type of phase transition, in contrast to the crossover reported for CeRu\(_2\)Si\(_2\). Analysis of the resistivity data shows a pronounced decrease of the electronic quasiparticle mass across \(H_c\). These results establish CeTiGe as a new metamagnetic Kondo-lattice system, with an exceptionally large, metamagnetic transition of first-order type at a moderate field.