Magnetocapacitance in CdCr1.8In0.2S4 Single Crystal Annealed in Cadmium Vapor

CdCr
₂
S
₄
single crystal was reported by Hemberger et al. to be multiferroic with the evidences of relaxor ferroelectricity and colossal magnetocapacitance (CMC), but whether these effects are intrinsic is under debate. Recently, we reported a one-to-one correlation between CMC and colossal magnetoresistance (CMR) in CdCr
₂
S
₄
polycrystalline samples, and argued that CMC could be explained by the superposition of the CMR and the Maxwell-Wagner effects. In this paper, we further examined the magnetic, dielectric, and electric transport properties of CdCr
₂
S
₄
and CdCr
_1.8
In
_0.2
S
₄
single crystals before and after annealing in cadmium vapor. The CdCr
₂
S
₄
single crystal sample has no relaxor ferroelectricity and CMC, and in contrast to the CdCr
₂
S
₄
single crystal reported by Hemberger et al., only the annealed CdCr
_1.8
In
_0.2
S
₄
displays CMC, but still does not exhibit the relaxor behavior. At the same time, it also shows CMR. All these results are in accordance with the results of our polycrystalline samples, and further confirm the resistive origin of the CMC in the CdCr
₂
S
₄
system.