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Magnetic and structural properties of cosputtered rare earth-iron-boron permanent-magnet films
Abstract
The samples for this study are of the form R$\sb2$Fe$\sb1$$\sb4$B:M (where R = Nd, Pr; M = Ag, Fe, Ta, or Pr). They were prepared in a multiple-gun sputtering system with a temperature-controlled substrate holder capable of reaching 700$\sp\circ$C. The R$\sb2$Fe$\sb1$$\sb4$B (RFB) was sputtered from a single alloy target. The RFB and M were deposited sequentially, 5 to 5000 A at a time onto Ta or mica substrates. The total film thickness was usually 1 $\mu$m. The structures of the films were studied by large-angle and small-angle x-ray diffraction and scanning electron microscopy. Their magnetic properties were studied with a room-temperature vibrating-sample magnetometer (VSM) with a maximum field of 17.1 kOe, and with a cryogenic VSM containing a superconducting solenoid capable of generating 80 kOe. A special heater was developed for the cryogenic VSM, and some of the samples were examined at room temperature in fields up to 80 kOe. It was found that the properties of these films depended strongly upon the material M and the individual layer thicknesses of M and RFB. The magnetization data were compared to coherent rotation, domain wall pinning, and reverse domain nucleation theories of magnetization reversal. The Pr$\sb2$Fe$\sb1$$\sb4$B:Pr films, for example, have the largest room-temperature coercivities (about 20 kOe), and the magnetization reversal is probably controlled by reverse domain nucleation.
Subject Area
Condensation
Recommended Citation
Aylesworth, Kevin Donald, "Magnetic and structural properties of cosputtered rare earth-iron-boron permanent-magnet films" (1989). ETD collection for University of Nebraska-Lincoln. AAI9019552.
https://digitalcommons.unl.edu/dissertations/AAI9019552