Pressure-dependence of the Colossal Magnetoresistance of Europium Cadmium Phosphorus (EuCd2P2)

Europium Cadmium Phosphorus (EuCd2P2) is a newly discovered strongly correlated electron system that exhibits colossal magnetoresistance (CMR) at ambient pressure [1] . Colossal Magnetoresistance is an important material property that can have pleothra of applications in  technology such as the construction of magnetic sensors, hard drives, anti- ferromagnetic spintronic devices etc. It is generally assumed that CMR is a property intrinsic to manganese oxides with mixed valence and a cubic perovskite structure. However, the strong CMR  seen in EuCd2P2 without manganese, oxygen or perovskite structures underscores a need for a more comprehensive theory of this phenomenon.

Pressure is an effective tool to tune the interactions in materials and allow testing theoretical hypotheses. In the case of EuCd2P2, it is known that the observed peak in the temperature dependence of the electrical resistivity occurs right above its neel temperature where it transitions from a paramagnetic material to an A-type anti–ferromagnetic (AFM) material.

In this study, we present the evolution of electrical resistivity and the AC magnetic susceptibility of EuCd2P2 as a function of pressure and temperature in a Diamond Anvil Cell (DAC) device. We also investigate the response of the electrical resistance to an external magnetic field to gain a deeper insight to the magnetic behavior and electron correlation properties of the material.We also present the supplementary study of the structural properties of EuCd2P2 under pressure to determine if there is any structural phase transition associated with the occurrence  of the colossal magnetoresistance. 

[1],[2] Wang, Zhi‐Cheng, et al. "Colossal magnetoresistance without mixed valence in a layered phosphide crystal." Advanced Materials 33.10 (2021): 2005755.