A New Method of Intergrain Exchange Interaction Energy Determination in Nanostructured Alloys with Spontaneous Spin-Reorientation Transition

A new method of intergrain exchange interaction energy determination in nanostructured magnetically hard alloys with spontaneous spin-reorientation transition has been developed and verified. It is based on the knowing of the material magnetic anisotropy constants values at its “easy cone” state and the external negative magnetic field strength H, which reversibly “tears” the exchange coupling between nanograins. It should be more than exchange field and smaller than coercivity value. Using this method the exchange interaction energy parameter for MQP-B+ alloy was estimated. Its value is in agreement with estimated one by FMR technique for film system Fe-Nd2Fe14B and close to that obtained from the remanent magnetization temperature dependences measurements in negative magnetic fields.