Diluted magnetic semiconductors (DMSs) represent a significant area of interest for research and applications in spintronics. Recently, DMSs derived from BaZn2As2 have garnered significant interest due to the record Curie temperature (TC) of 260 K. However, the influence of doping on their magnetic evolution and transport characteristics has not been thoroughly investigated. This study aims to fill this gap through susceptibility and magnetization measurements, electric transport analysis, and muon spin relaxation and rotation (µSR) measurements on (Ba1-xRbx)(Zn1-yMny)2As2 (0.1 ≤ x, y ≤ 0.25, BRZMA). Key findings include the following: (1) BRZMA showed a maximum TC of 138 K, much lower than (Ba,K)(Zn,Mn)2As, because of a reduced carrier concentration. (2) A substantial electromagnetic coupling is evidenced by a negative magnetoresistance of up to 34% observed in optimally doped BRZMA. (3) A 100% static magnetic ordered volume fraction is achieved in the low-temperature region, indicating a homogeneous magnet. (4) Furthermore, a systematic and innovative methodology has been initially proposed, characterized by clear step-by-step instructions aimed at enhancing TC, grounded in robust experimental findings. The findings presented provide valuable insights into the spin-charge interplay concerning magnetic and electronic transport properties. Furthermore, they offer clear direction for the investigation of higher TC DMSs.
Keywords: Curie temperature; carrier concentration; colossal magnetoresistance; diluted magnetic semiconductor; homogeneous ferromagnets.