Physical measurements in a permanent magnet field varying spatially

A high-field permanent magnet with the field varying from -2.6 to +2.6 T over a distance of 23 cm has been constructed for Virginia State University by Neomax Inc. The field varies along a 52-cm-long access port with a square cross section of 12x12 mm(2). The purpose of this magnet is to facilitate measurements in an arbitrary sequence of fields in which the position of the sample determines the applied field. The maximum field is high enough that the demagnetizing fields for thin oblate spheroids can be overcome for any known ferromagnetic material. The use of this magnet in an induction magnetometer is demonstrated. (C) 2006 American Institute of Physics.