Specific heat anomaly in CePd2Al3 single crystals below 1K

Abstract CePd 2 Al 3 is known for the peculiarity that single crystals do not show long-range magnetic order while well-annealed polycrystals become antiferromagnetic below 2.7 K. Disorder on the Al sites in the single crystals was suggested to be responsible for this difference in phenomenological behavior. Here specific heat results on single crystals in an extended temperature range down to 0.3 K and under magnetic fields to 10 T are reported. Close to 0.8 K a rather broad anomaly shows up which has no similarity to a long-range order (LRO) phase transition. Since it is shifted to higher temperatures and smeared out by the field it is magnetic in origin and gives evidence of magnetic short-range correlations. These, however, do not lead to LRO because of the disorder on the Al planes. Uniaxial compression by 1.1 kbar parallel to the c -axis was not sufficient to induce magnetic LRO by increasing the RKKY interaction in this direction.