A CaAl 2 Si 2 -Type Magnetic Semiconductor (Sr, Na)(Zn, Mn)2Sb2 Isostructural to 122-Type Iron-Based Superconductors

Abstract

A new diluted magnetic semiconductor (Sr, Na)(Zn, Mn)2Sb2 has been successfully synthesized by doping Na and Mn into the parent compound ${\text{SrZn}}_2{\text{Sb}}_2$ , which has a ${\text{CaAl}}_2{\text{Si}}_2$ -type crystal structure (space group $P\overline{3}m1$ , No. 164, $hP5$ ) isostructural to the 122-type iron-based superconductor ${\text{CaFe}}_2{\text{As}}_2$ . No magnetic ordering has been observed when only spins are doped by (Zn, Mn) substitution. Only with carriers codoped by (Sr, Na) substitution, a ferromagnetic ordering occurs below the maximum Curie temperature $T_C$ ∼9.5 K. Comparing with other ${\text{CaAl}}_2{\text{Si}}_2$ -type diluted magnetic semiconductors, we will show that negative chemical pressure suppresses the Curie temperature.