TY - JOUR
T1 - Macroscopic electrical field distribution and field-induced surface stresses of needle-shaped field emitters
AU - Moy, Charles K.S.
AU - Ranzi, Gianluca
AU - Petersen, Timothy C.
AU - Ringer, Simon P.
N1 - Funding Information:
The authors acknowledge gratefully part-funding of this research from the Australian Research Council and are grateful for scientific and technical input and support from the Australian Microscopy & Microanalysis Research Facility (AMMRF) node at the University of Sydney. In particular, fruitful discussion and suggestions from Dr. B. Gault are gratefully appreciated. The authors also acknowledge Prof. Igor M. Mikhailovskij from Kharkov Institute of Physics and Technology for pointing out an error in the manuscript.
PY - 2011
Y1 - 2011
N2 - One major concern since the development of the field ion microscope is the mechanical strength of the specimens. The macroscopic shape of the imaging tip greatly influences field-induced stresses and there is merit in further study of this phenomenon from a classical perspective. Understanding the geometrical, as opposed to localized electronic, factors that affect the stress might improve the quality and success rate of atom probe experiments. This study uses macroscopic electrostatic principles and finite element modelling to investigate field-induced stresses in relation to the shape of the tip. Three two-dimensional idealized models are considered, namely hyperbolic, parabolic and sphere-on-orthogonal-cone; the shapes of which are compared to experimental tips prepared by electro-polishing. Three dimensional morphologies of both a nano-porous and single-crystal aluminium tip are measured using electron tomography to quantitatively test the assumption of cylindrical symmetry for electro-polished tips. The porous tip was prepared and studied to demonstrate a fragile specimen for which such finite element studies could determine potential mechanical failure, prior to any exhaustive atom probe investigation.
AB - One major concern since the development of the field ion microscope is the mechanical strength of the specimens. The macroscopic shape of the imaging tip greatly influences field-induced stresses and there is merit in further study of this phenomenon from a classical perspective. Understanding the geometrical, as opposed to localized electronic, factors that affect the stress might improve the quality and success rate of atom probe experiments. This study uses macroscopic electrostatic principles and finite element modelling to investigate field-induced stresses in relation to the shape of the tip. Three two-dimensional idealized models are considered, namely hyperbolic, parabolic and sphere-on-orthogonal-cone; the shapes of which are compared to experimental tips prepared by electro-polishing. Three dimensional morphologies of both a nano-porous and single-crystal aluminium tip are measured using electron tomography to quantitatively test the assumption of cylindrical symmetry for electro-polished tips. The porous tip was prepared and studied to demonstrate a fragile specimen for which such finite element studies could determine potential mechanical failure, prior to any exhaustive atom probe investigation.
KW - Atom probe
KW - Field ion microscope
KW - Field-induced surface stresses
KW - Needle-shaped emitters
UR - http://www.scopus.com/inward/record.url?scp=80052529246&partnerID=8YFLogxK
U2 - 10.1016/j.ultramic.2011.01.024
DO - 10.1016/j.ultramic.2011.01.024
M3 - Article
AN - SCOPUS:80052529246
SN - 0304-3991
VL - 111
SP - 397
EP - 404
JO - Ultramicroscopy
JF - Ultramicroscopy
IS - 6
ER -