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Title: Indentation recovery in GdPO 4 and observation of deformation twinning

A series of nanoindentation tests on both single and polycrystalline specimens of a monazite rare-earth orthophosphate, GdPO 4, revealed frequent observation of anomalous unloading behavior with a large degree of recovery, where previously this behavior had only been observed in xenotime-structure rare-earth orthophosphates. An indentation site in the polycrystalline sample was examined using TEM to identify the deformation mechanism responsible for recovery. Finally, the presence of a twin along the (100) orientation, along with a series of stacking faults contained within the deformation site, provide evidence that the mechanism of recovery in GdPO 4 is the collapse of deformation twins during unloading.
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  1. Colorado School of Mines, Golden, CO (United States). Dept. of Metallurgical and Materials Engineering
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division
Publication Date:
Grant/Contract Number:
AC05-00OR22725; DMR-1352499
Published Article
Journal Name:
AIP Advances
Additional Journal Information:
Journal Volume: 6; Journal Issue: 9; Journal ID: ISSN 2158-3226
American Institute of Physics (AIP)
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Colorado School of Mines, Golden, CO (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Science Foundation (NSF)
Country of Publication:
United States
36 MATERIALS SCIENCE; polycrystals; hardness; nanotechnology; phase transitions; single crystals
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1327665; OSTI ID: 1420518