Magnetic behavior of pressure-quenched CdS containing Cl

Pressure-quenched CdS containing Cl has been shown previously to exhibit both very large diamagnetism and paramagnetism. The diamagnetism observed at 77 K approached Meissner proportion and suggested superconductinglike behavior in this material. The effect is known to depend sensitively on the Cl content of the starting material. This paper describes the results of a survey of the magnetic behavior of pressure-quenched samples prepared from CdS systematically doped with increasing amounts of Cl. The Cl-doped material was prepared in a variety of ways: from mixtures of CdS and Cd${\mathrm{Cl}}_2$, by precipitation from aqueous solution, and by acid doping. The differently doped starting materials were analyzed for Cl and other impurities before being pressure quenched. The magnetic susceptibilities were subsequently measured. The results of the survey indicate that the concentration of Cl required to produce specimens with anomalously large magnetism is 0.75±0.10 wt.%. The technique for the preparation of such material is described.