Structural, Mössbauer Spectroscopy and Ab-initio Calculations Investigation of ´-Fe4N-GaN Nanocomposites

S. KURIAN; S. BHATTACHARYYA; J. DESIMONI; E. L. PELTZER Y BLANCÁ; A. V. GIL REBAZA; N. S. GAJBHIYE

Universidad Mayor de San Carlos, Lima, Perú

Conferencia; XII Latin American Conference on the Application of the Mössbaueer Effects (LACAME); 2010

Latin American Conference on the Application of the Mössbaueer Effects

A controlled one step ammonolysis method with three different Fe:Ga ratios (70:30, 50:50 and 30:70) was used to synthesize functional nanocomposite material consisting of 30-40 nm particles of g’-Fe4N, Fe4-xGaxN phases in a GaN and Fe-doped GaN phase matrix. The g’-Fe4N, Fe4-xGaxN, GaN phases is confirmed by Rietveld analysis of the X-Ray diffraction patterns, while Fe-doped GaN was established from Mössbauer sprectroscopy that showed a hyperfine magnetic field distribution. Structural and hyperfine characterization are put together with the ab-initio calculations, performed using FP-LAPW method within the framework of DFT as implemented in the Wien2k code. The agreement of the lattice parameters obtained from ab-initio calculations and the experimental ones reinforce the hypothesis of the formation of Fe4-xGaxN. Even though the Mössbauer spectra at 5K shows a complex structure, existence of all the phases are confirmed by analysis of the spectra and the magnetic hyperfine fields obtained from  ab-initio calculation.