Crystal electric fields and the anomalous high-temperature phase transition in Ce2Rh2Ga

Compounds of the element Cerium occupy a special place in contemporary condensed matter physics. These materials have become known for a unconventional magnetism and superconductivity, as well as new phases of matter at very low temperatures. The subject of this proposal, Ce2Rh2Ga, has a phase transition at 130 K which is extraordinary for a cerium compound. Sharp anomalies are found in the temperature dependence of physical properties probed thus far including magnetic susceptibility, electrical and thermal transport, and specific heat. In agreement with magnetic susceptibility data, Ga-NQR data support an interpretation in terms of a magnetic phase transition which would make this the highest recorded magnetic phase transition among all cerium compounds. This proposal is to map the crystal electric field landscape in Ce2Rh2Ga and to understand the origin of its unusual ordering.