Comparative Study of the Magnetic Susceptibility of n-Ge near the Insulator–Metal Phase Transition by Means of ESR and SQUID

Impurity paramagnetic susceptibility of n-Ge has been measured in the vicinity of the insulator– metal phase transition by two techniques: ESR and SQUID. A comparison of these methods demonstrated that their results qualitatively coincide at low temperatures, but differ at high temperatures. The advantage of the ESR technique is in its substantially higher relative precision, but SQUID makes it possible to obtain on principle absolute values of the magnetic susceptibility. It was found that, in the present-day state of development, the SQUID method has a substantially poorer precision, compared with ESR