Dresden 2009 – wissenschaftliches Programm
MM 10.3: Vortrag
Montag, 23. März 2009, 16:30–16:45, IFW B
Characterization of MAX phases via hyperfine interactions — •Daniel Jürgens1, Michael Uhrmacher1, Hans Hofsäss1, Agnieszka Kulinska1, 2, Jose Mestnik Filho3, and Michel Barsoum4 — 1II. Physikalisches Institut, Universität Göttingen, 37073 Göttingen, Germany — 2IFJ PAN, 31-342 Krakow, Poland — 3Instituto de Pesquisas Energeticas e Nucleares, 05422-970 Sao Paulo, Brazil — 4Dep. Mat. Science and Eng. Drexel University, Philadelphia, PA 19104, USA
Mn+1AXn phases, where n is 1, 2 or 3, are nanolaminated layered ternary carbides and nitrides, which feature a unique combination of the best attributes of both metals and high-performance ceramics. This class of solids possesses good electrical and thermal conductivities as well as high thermal shock resistance and damage tolerance.
The method of perturbed angular correlation (PAC), which is sensitive to hyperfine interactions, is used for material characterization on microscopic scale. 111In was implanted as probe nuclei to measure the electric field gradients (EFG) in the key-compounds Ti2InC and Zr2InC to determine strength and symmetry of the EFG on the In-site or more general on the A-site. Regarding to the question of lattice location of In-probes in In-free MAX phases, PAC studies of Ti2AlN and Cr2GeC were performed to confirm the assumption occupying the A-site. The experimental results are compared with those from ab initio calculations using the FP-LAPW+LO method implemented in the WIEN2k code. Additionally investigations of annealing behavior, thermal stability and behavior under isostatic stresses are presented.