Previous measurements on pressure-quenched CdS have revealed anomalous magnetic susceptibility indicative of high-temperature superconductivity, but only over a narrow critical range of chlorine doping. X-ray-diffraction studies as a function of chlorine doping now show that at the critical chlorine doping the material undergoes a phase transition, leaving it as wurzite. Photoacoustic spectroscopy shows that a soft lattice mode appears just beyond critical doping, over the same range as the anomalous magnetism. Lastly, we find by analysis that superparacurrent is induced by a magnetic field in wurzite, providing the lattice mode associated with the wurzite zinc-blende phase transition is very soft.

• Received 12 June 1987

DOI:https://doi.org/10.1103/PhysRevB.37.3275