Berlin 2018 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 41: Liquid and Amorphous Metals

MM 41.5: Vortrag

Mittwoch, 14. März 2018, 16:15–16:30, TC 010

Synthesis and characterization of Tb75Fe25 nanoglass — •Shiv Prakash Singh, Herbert Gleiter, and Horst Hahn — Institute of Nanotechnology, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany

Nanoglasses have been developed with the original idea to generate a new kind of amorphous material, by the controlled introduction of defects and alterations of the chemical microstructure. This approach is similar to that used in nanocrystalline materials. In this work, we have synthesized a Tb75Fe25 nanoglass using the inert gas condensation method, by compaction of nanometer sized Tb75Fe25 glassy particles at 3 GPa. The as prepared nanoglass specimen (NG) was subjected to high pressure torsion (HPT) at 6 GPa with three complete rotations. X-ray diffraction pattern for the NG and the nanoglass specimen prepared using HPT (NGT) demonstrate the amorphous nature. Transmission electron microscopy revealed the amorphous structure with a small fraction of a crystalline phase for both NG and NGT. Differential scanning calorimetry demonstrated a lower crystallization temperature for the NGT in comparison to the NG. The NG showed a higher coercivity and lower magnetization than the NGT at 1.8K. The above NG and NGT specimens have then been heat treated at 390 oC for 30 minutes. The coercivity decreased for both heat treated samples compared to NG and NGT due to evolution of iron reach crystalline phase (Fe2Tb).