Raymond Browning of R. Browning Consultants has developed a first-of-its-kind X-ray photoelectron spectroscopic microscope at the Brookhaven National Laboratory of the U.S. Department of Energy.
Dan Fischer (left) and Raymond Browning show off the prototype of the Vector Potential Photoelectron Microscope.
The Small Business Innovation and Research program of the National Institute of Standards and Technology (NIST) funded for the development of the advanced microscope.
The prototype of this sophisticated microscope, a vector potential photoelectron microscope (VPPEM) has been developed in partnership with the NIST Synchrotron Methods Group at the National Synchrotron Light Source (NSLS) of the Brookhaven National Laboratory.
Using a novel imaging method, the new microscope can be used for studying technologically significant material systems. The VPPEM is capable of delivering a spatial resolution thousand folds higher than that of existing technology and is anticipated to be the most sophisticated general purpose X-ray photoelectron microscope of the world when used with the beamline of the NIST at NSLS-II, the new light source being developed at the Brookhaven National Laboratory.
The VPPEM employs X-ray photoelectron spectroscopy to picture the chemistry and composition of surfaces in order to identify the performance properties of a material, including hardness, strength, utility in fuel cells and corrosion resistance. The VPPEM images provide data useful for analyzing defects in semiconductor equipment, characterizing of organic photovoltaic materials, analyzing surfaces utilized in medical practice, developing innovative materials, analyzing interface and surface of general materials.
The VPPEM magnifies a sample by using an intensified vector potential field generated by a superconducting coil instead of a conventional lens system. The equipment utilizes a symmetric field formed by the vector potential field as spatial reference or a two-dimensional map for picturing samples. As it does not use imaging lens, imaging of samples can be done, as they are constantly in focus even when they are placed at various locations in the vector potential field. It requires minimal sample preparation for imaging even with comparatively larger, irregular samples.
Browning stated that the VPPEM magnifies the vector potential field impact on the photoelectrons released from the sample. When synchrotron-generated X-rays is utilized to irradiate the surface of a sample, the surface atoms release typical photoelectron energies to get data about chemical bonding, atom types and to some extent, a material’s atomic structure, Browning said.
Dan Fischer, who leads the NIST Synchrotron Methods Group, stated that as the novel microscope focuses automatically, it is user friendly and does not require knowledge of synchrotrons. Once completely built, this equipment will be a major tool in the NSLS-II that will offer continuous three-dimensional mapping of nanodevices and nanomaterials, Fischer concluded.