Texture determinations in rare-earth-based permanent magnets

Quantifying the relationship between crystallographic texture and magnetic properties is highly desirable for the engineering high (BH){sub max} magnets. Existing techniques for the evaluation of texture in permanent magnets often rely upon magnetic remanence measurements. However, such determinations are strictly applicable only to assemblies of non-interacting particles, which nullifies the use of the Stoner-Wohlfarth criteria in texture determinations of ``exchange-spring`` magnets. New techniques in the determination of texture of bulk permanent magnets are being developed to overcome these inherent experimental difficulties. Crystallographic alignment studied by transmission synchrotron x-ray diffraction as a function of position within the sample reveals insights into the development of texture with deformation level in thermomechanically-processed magnets. Information concerning texture may also be obtained by a different method based on paramagnetic susceptibility measurements. Such measurements also provide Curie temperature data, which is sensitive to chemical changes that may have occurred in the magnetic phase during processing