Homogeneous limit of Cd1−xMnxGeAs2 alloy: Electrical and magnetic properties

Abstract

We present the studies of structural, electrical, and magnetic properties of bulk Cd 1-x Mn x GeAs 2 crystals with low Mn content, x, varying from 0 to 0.037. The studied samples have excellent crystallographic quality indicated by the presence of diffraction patterns never before observed experimentally for this compound. The electrical transport in our samples is dominated by thermal activation of conducting holes from the impurity states to the valence band with activation energy of about 200 meV. The defect states acting as ionic scattering centers with concentration in the range from 6 to 15×10 17 cm −3 are observed. The effective Mn content in our samples,x θ , determined from fit of the susceptibility data to the Curie-Weiss law, is very close to the average chemical content, x. It indicates that the Mn ions are distributed randomly, substituting the Cd sites in the host CdGeAs 2 lattice. We observe a negative Curie-Weiss temperature, |θ| ≤ 3.1 K, increasing as a function of x. This indicates the significance of the short-range interactions between the Mn ions.

X‐ray powder diffraction study of chalcopyrite‐type Cd1 − xMnxGeAs2 crystals

“…We suppose that some contribution to this effect can be due to magnetic interactions. As it is shown by Kilanski et al ,. the Cd 1 − x Mn x GeAs 2 alloys with low content of Mn reveal paramagnetic (PM) behavior at room temperature because of random distribution of Mn ions which results in the short‐range interactions between them.…”

Composites based on self-assembled MnAs ferromagnet nanoclusters embedded in ZnSnAs2 semiconductor

“…5b). The paramagnetic Mn ions present in ZnSnAs 2 lattice are not unexpected because the solubility of magnetic ions in the II-IV-V 2 lattice is only few molar percents in ZnGeAs 2[22] and CdGeAs 2[23].…”

High temperature magnetic order in Zn1−xMnxSnSb2+MnSb nanocomposite ferromagnetic semiconductors

“…It has been proven that the short-range magnetic interactions connected with the presence of magnetic clusters are responsible for hightemperature ferromagnetism in Mn-alloyed II-IV-V 2 crystals [7][8][9]. Large solubility of Mn ions equal to about ≈ x 0.053 in Zn 1−x Mn x GeAs 2 [10,11] and ≈ x 0.045 in Cd 1−x Mn x GeAs 2 [12,13] crystals grown under thermodynamical equilibrium conditions and a rather large value of the Mn-ion conducting hole magnetic exchange constant, ≈ ± J 0.75 0.09 pd eV, have…”