“…[9][10][11][12][13] The preparation of DMS mainly uses transition metal atoms or rare earth ions, which have spin magnetic moment, doped to substitute some atoms in the semiconductor material. [14][15][16] The magnetic moment of DMS is produced by the exchange of p state electrons of the anions and d state electrons of the magnetic ions, which are changed by the external temperature and doping concentration, so they may be ferromagnetic, sub ferromagnetic and antimagnetic. 17,18 As a new type of II-VI narrow band gap semiconductor, Ca 2 Ge has high T C , high carrier mobility, low dielectric constant, and excellent optical and other properties.…”