Abstract: A magnetometer in which at least two modes of drive are employed in exciting sensor and/or sample so that the sensor provides an output indication of magnetic moment which is a function of both drive modes. The drive modes may be periodic at specific driving frequencies, aperiodic or may comprise a unidirectional portion of a mode. The output of the sensor contains components representative of the frequency or frequencies of the first mode modulated at the frequency or frequencies of the second mode. This sensor output is then analyzed to provide an indication of sample magnetic moment as a function of the frequency components of both modes of drive in order to eliminate contributions to the indicated magnetic moment from background signals or other perturbations which may be present under single mode operation.

Abstract: The method of preparing Pb.sub.x Mo.sub.y S.sub.z where x = 0.8-1.1, y = 4.5-5.6, and z = 5.4-7.2 comprising the steps of mixing commercial reagent grade powders of the reactants, heating in a sealed, evacuated reaction vessel to a temperature of 950.degree.-1150.degree. C, maintaining the temperature until the compound is formed, and then cooling the compound at a controlled rate not in excess of 4.degree. C per minute.

Abstract: An improved magnetometer for measuring the magnetic moment of a sample. Signals representative of magnetic moment are provided in known phase relation with respect to a driving signal and in phase with the motion of the sample, while spurious signals, such as produced by eddy currents are in an out-of-phase relationship with sample motion. Distortions in the measured magnetic moment due to eddy currents and other out-of-phase spurious signals are eliminated by cancellation of the out-of-phase signals through an AC feedback network.An output signal comprising the magnetic moment signal and spurious signals is applied to a phase sensitive detector whose DC output represents the amplitude of the spurious out-of-phase signal which it is sought to eliminate.