The magnetic properties of high i H c Sm-Co, Nd-Fe-B, and Sm-Ti-Fe films crystallized from amorphous deposits

Abstract

Permanent magnet films of the compounds SmCo₅, Nd₂Fe₁₄B, and a high intrinsic coercive force, _iH_c, Sm‐Ti‐Fe phase have been prepared by a two‐stage process in which the appropriate compositions were first deposited with a magnetic field applied in the substrate plane, and then subsequently crystallized in situ in this same magnetic field. The resulting samples exhibited high _iH_c values and specular reflecting surfaces. For the case of SmCo₅ and for the high _iH_c Sm‐Ti‐Fe phase, samples were synthesized that exhibited extreme in‐the‐film‐plane anisotropy. For these SmCo₅ and high _iH_c Sm‐Ti‐Fe samples magnetic measurements, made at room temperature, indicated an in‐the‐film‐plane anisotropy constant of at least 10⁷ erg/cm³ for magnetizing the films in the film plane parallel versus perpendicular to the field that had been applied during the sputter deposition and crystallization. A model is presented based upon the crystallite grain sizes and magnetic alignment energy that correlates the differences in the degree of in‐the‐film‐plane anisotropy induced in these systems. The model is applied to these systems as prepared by crystallizing amorphous deposits, and as directly crystallized onto heated substrates.