Superconductivity in CuAl₂-type Co_0.2Ni_0.1Cu_0.1Rh_0.3Ir_0.3Zr₂ with a high-entropy-alloy transition metal site

Figures & data

Table 1. Crystal structure type, space group, and T_c of TrZr₂ and related phases (Tr = Co, Ni, Cu, Rh, Ir).

Phase	Structural type	Space group	Tc (K)	Reference (Tc)
CoZr2	CuAl2-type	I4/mcm (No. 140)	5.5–6.0	[27, this work]
NiZr2	CuAl2-type	I4/mcm (No. 140)	1.6	[27]
RhZr2	CuAl2-type	I4/mcm (No. 140)	11.3	[27]
IrZr2	CuAl2-type	I4/mcm (No. 140)	7.5	[27]
FeZr2	CuAl2-type	I4/mcm (No. 140)	< 1 K	[28,29]
CuZr2	CuZr2-type	I4/mmm (No. 139)	–	–
Co0.9Cu0.1Zr2	CuAl2-type	I4/mcm (No. 140)	6.1	[30]
Co0.2Ni0.1Cu0.1Rh0.3Ir0.3Zr2	CuAl2-type	I4/mcm (No. 140)	7.8	This work

Figure 1. (a) XRD pattern and Rietveld fitting for Co_0.2Ni_0.1Cu_0.1Rh_0.3Ir_0.3Zr₂. The numbers in the figure are Miller indices. (b, c) Schematic images of crystal structure of CuAl₂-type Co_0.2Ni_0.1Cu_0.1Rh_0.3Ir_0.3Zr₂.

Figure 2. (a) Temperature dependence of (ZFC and FC) susceptibility (4πχ) for Co_0.2Ni_0.1Cu_0.1Rh_0.3Ir_0.3Zr₂. (b) Magnetic field dependence of magnetization for Co_0.2Ni_0.1Cu_0.1Rh_0.3Ir_0.3Zr₂ taken at T = 2.5 K. The inset shows low-field M-H data.

Figure 3. (a) Temperature dependences of electrical resistivity for Co_0.2Ni_0.1Cu_0.1Rh_0.3Ir_0.3Zr₂. (b) Temperature dependences of resistivity for Co_0.2Ni_0.1Cu_0.1Rh_0.3Ir_0.3Zr₂ under magnetic fields. (c) Magnetic field-temperature phase diagram for Co_0.2Ni_0.1Cu_0.1Rh_0.3Ir_0.3Zr₂.

Figure 4. (a) Temperature dependence of C/T for Co_0.2Ni_0.1Cu_0.1Rh_0.3Ir_0.3Zr₂ at 0 and 9 T. (b) Temperature dependence of electronic specific heat C_el/T at 0 T.

Fisk Z, Viswanathan R, Webb GW. The relation between normal state properties and Tc FOR SOME Zr2X compounds. Solid State Commun. 1974;15:1797–1799.

 Web of Science ®Google Scholar

Matthias BT, Corenzwit E. Superconductivity of zirconium alloys. Phys Rev. 1955;100:626–627.

 Google Scholar

Lefebvre J, Hilke M, Altounian Z. Superconductivity and short-range order in metallic glasses FexNi1-xZr2. Phys Rev B. 2009;79(1–8):184525.

 Google Scholar

Syu KJ, Chen SC, Wu HH, et al. Superconductivity in Zr2(Co1−xCux). Physica C. 2013;495:10–14.

 Web of Science ®Google Scholar