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Materials with thermally compensating properties for devices using magnetostatic waves
Results are presented of investigations of the temperature dependence of the frequency of the surface magnetostatic waves in the cubic ferrite film—permanent magnet system. Analysis made of the conditions of thermal stability of the frequency and the essential requirements are proposed for the parameters of the film and the magnet. The results show that the best thermally compensating properties are typical of the films with the orientation {110} and magnets with positive temperature coefficients of spontaneous magnetisation. The experimental investigations were carried out on films of iron-yttrium garnet and magnets of (NdDy Tb Ho Gd) (Fe Co) В alloys. The temperature dependences of the frequencies from the longwave part of the spectrum were characterised by non-monotonic sections. At the maximum of the dependences, the temperature coefficients showed the zero value. The highest thermally stable frequency, 4.6 GHz, was recorded in the field with a strength of 1070 Oe and a temperature coefficients of 0.3 Oe/°C.