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The correlated electron material CePd2P2 crystallizes in the ThCr2Si2 structure and orders ferromagnetically at 29 K. Prior work by Lai et al. [Phys. Rev. B 97, 224406 (2018)] found evidence for a ferromagnetic quantum critical point induced by chemical compression via substitution of Ni for Pd. However, disorder effects due to the chemical substitution interfere with a simple analysis of the possible critical behavior. In the present paper, we examine the temperature—pressure—magnetic-field phase diagram of single crystalline CePd2P2 to 25 GPa using a combination of resistivity, magnetic susceptibility, and x-ray diffraction measurements. We find that the ferromagnetism appears to bemore »destroyed near 12 GPa, without any change in the crystal structure.« less

High entropy alloys (HEA) are an unusual class of materials where mixtures of elements are stochastically arrayed on a simple crystalline lattice. These systems exhibit remarkable functionality, often along several distinct axes: e.g., the examples [TaNb]_1-x(TiZrHf)_xare high strength and damage resistant refractory metals that also exhibit superconductivity with large upper critical fields. Here we report the discovery of anf-electron containing HEA, [TaNb]_0.31(TiUHf)_0.69, which is the first to include an actinide ion. Similar to the Zr-analogue, this material crystallizes in a body-centered cubic lattice with the lattice constanta = 3.41(1) Å and exhibits phonon mediated superconductivity with a transition temperaturesT_c ≈ 3.2 K and uppermore »critical fieldsH_c2 ≈ 6.4 T. These results expand this class of materials to include actinide elements, shows that superconductivity is robust in this sub-group, and opens the path towards leveraging HEAs as functional waste forms for a variety of radioisotopes.

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