A WIDE TEMPERATURE-RANGE SUSCEPTOMETER

A new type of high-sensitivity magnetic susceptometer is proposed. It utilises a long thin vibrating wire as a sample support, which is driv en at resonance by an alternating field gradient, with no applied de f ield. The gradient is generated by a tiny soft ferromagnetic rod close to the sample. The chosen configuration is particularly suitable to p erform measurements on thin films and small samples in a wide temperat ure range (up to 1200 K). A realised prototype for high temperatures i s described, with a few examples of measurements. An analysis of the m oment sensitivity and considerations on the noise are given, with indi cations of the physical limits of the technique. A moment sensitivity of the order of 10(-11) A . m(2)/root Hz, with an alternating field of 100 A/m, is estimated for the present prototype.