Ab initio density functional calculations, transmission electron microscope, and x-ray diffraction (XRD) were used to study the dominant factor of increased coercivity for the doping effect in SmCo 7-xZr x (x = 0 to 0.3). Simulated values of saturated magnetization are 940 emu/cm 3 for SmCo 7 and 799 emu/cm 3 for SmCo 6.7Zr 0.3, which agree with experimental results within 6. The calculated anisotropy constant (for 2e) increases from 1.151 ? 10 7 erg/cm 3 for SmCo 7 to 1.934 ? 10 7 erg/cm 3 for SmCo 6.7Zr 0.3. The grain sizes remain almost the same by adding ?4 (atomic percent) Zr through the analyses of XRD. The increased anisotropy is the dominated factor for enhancing the coercivity in SmCo 6.7Zr 0.3. In addition, both results of Rietveld refinements of XRD data and ab initio calculations show that Zr situating at 2e/3g positions are more stable than 2e/2e locations, which were suggested conventionally. ? 2011 American Institute of Physics.
Relation:
Journal of Applied Physics 109 (7) , art. no. 07A748
