Choi, Pyuck-Pa Al-Kassab, Tala&apos;at Kwon, Young-Soon Kim, Ji-Soon Kirchheim, Reiner 2024-01-21T00:31:38Z 2024-01-21T00:31:38Z 2021-09-02 2007-10 1431-9276 https://pubs.kist.re.kr/handle/201004/134086 Focused ion-beam milling has been applied to prepare needle-shaped atom probe tomography specimens from mechanically alloyed powders without the use of embedding media. The lift-out technique known from transmission electron microscopy specimen preparation was modified to cut micron-sized square cross-sectional blanks out of single powder particles. A sequence of rectangular cuts and annular milling showed the highest efficiency for sharpening the blanks to tips. First atom probe results on a Fe95Cu5 powder mechanically alloyed in a high-energy planetary ball mill for 20 h have been obtained. Concentration profiles taken from this powder sample showed that the Cu distribution is inhomogeneous on a nanoscale and that the mechanical alloying process has not been completed yet. In addition, small clusters of oxygen, stemming from the ball milling process, have been detected. Annular milling with 30 keV Ga ions and beam currents >= 50 pA was found to cause the formation of an amorphous surface layer, whereas no structural changes could be observed for beam currents <= 10 pA. English CAMBRIDGE UNIV PRESS LIFT-OUT MICROSCOPY TEM Application of focused ion beam to atom probe tomography specimen preparation from mechanically alloyed powders Article 10.1017/S1431927607070717 1 MICROSCOPY AND MICROANALYSIS, v.13, no.5, pp.347 - 353 MICROSCOPY AND MICROANALYSIS 13 5 347 353 scie scopus 000250127700006 2-s2.0-34948816115 Materials Science, Multidisciplinary Microscopy Materials Science Microscopy Article LIFT-OUT MICROSCOPY TEM atom probe tomography mechanically alloyed powder focused ion beam in situ lift-out technique nanocrystalline materials