Date of Award
Master of Science
Sanjay R. Mishra
M. Shah Jahan
Parmanent magnetic material finds indutrial application ranging from motors, generators to computers, space vehicles and biomedical industries. There is a constant drive to improve magnetic properties to meet the emerging industrial demands. In the present study, rare-earth -TM intermetallics of type R2Fe17 is investigated, with specific aims of improving Curie temperature and along with to understand the structural and magnetic properties of these compounds.Series of Gd2Fe17 type substituted intermetallic compounds were carefully synthesized via arc melting. Gd2Fe17-xTix (x = 0, 0.25, 0.5, 0.75, 1, 1.25, 1.5) and Gd2Fe16Ga1-xTix (x = 0, 0.25, 0.5, 0.75, 1) were explored to understand the effect of substitution atoms on the net magnetic properties along with Curie temperature of the compound. A series of refractory metal doped Gd2Fe16Ga0.5RM0.5 (RM = Ti, V, Zr, Nb, Mo, W) were also explored to understand the role of refractory element doping on the phase formation and its effect on magnetic properties.Series of experiements with x-ray diffraction, vibration sample magnetometer and Mossbauer analysis revealed that the Ti substitution for Fe in Gd2Fe17-xTix improves the magnetic properties (Tc = 559 K) as compared to Gd2Fe17. On the other hand Tc of Gd2Fe16Ga1-xTix compound decreased with Ti substitution. The Tc variation in these compounds is related to the magnetovolume and exchange-interaction between Fe-Fe atoms. The magnetization reducction in Gd2Fe17-xTix was attributed to dilution effect while that in Gd2Fe16Ga1-xTix was related to hybridization of 3d Fe band.
dissertation or thesis originally submitted to the local University of Memphis Electronic Theses & dissertation (ETD) Repository.
Pokharel, Ganesh, "Structural, Magnetic and Mossbauer Spectral Study Of Gd2Fe16Ga0.5RM0.5 (RM = Ti, V, Zr, Nb, Mo, W), Gd2Fe17-xTix (x = 0- 1.5) and Gd2Fe16Ga1-xTix (x = 0 1) Intermetallic Compounds" (2013). Electronic Theses and Dissertations. 773.