Using an optimized-basis Korringa-Kohn-Rostoker-coherent-potential approximation method, we calculate formation enthalpies $\Delta E_f$, structural, and magnetic properties of paramagnetic (PM) and ferromagnetic, disordered A1 and ordered $\text{L}{1}_0$ CoPt, FePd, and FePt systems that are of interest for high-density magnetic-recording media. To address processing effects, we focus on the point defects that dictate thermal properties and planar defects (e.g., $c$ domain and antiphase boundaries) which can serve as pinning centers for magnetic domains and affect storage properties. We determine bulk Curie $\left(T_c\right)$ and order-disorder $\left(T_{\text{o-d}}\right)$ transition temperatures within 4% of observed values, and estimates for nanoparticles. Planar-defect energies ${\gamma }_x^{hkl}$ show that the favorable $\left[hkl\right]$ defects depend on processing conditions as $T_c<T_{\text{o-d}}$ in these alloys, and the PM defects agree with those observed. We correlate all properties with the electronic structure.

• Received 18 February 2010

DOI:https://doi.org/10.1103/PhysRevB.82.024435