Anomalous physical properties in nonstoichiometric Gd monopnictides

The large stoichiometric and nonstoichiometric GdP and GdAs single crystals have been grown by the mineralization method. Magnetic and transport properties of the stoichiometric and nonstoichiometric samples are found to be very different. The stoichiometric GdP and GdAs show the magnetic and transport properties which can be explained very well by the molecular field approximation. Correspondingly, the nonstoichiometric samples show some anomalies in the magnetic and transport properties which can be considered as evidences of the formation of trapped magnetic polaron states in nonstoichiometric gadolinium monopnictide systems. (author)