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John S. Villarrubia (Fed)

John Villarrubia is a physicist and project leader in the Microsystems and Nanotechnology Division of the Physical Measurement Laboratory (PML) at the National Institute of Standards and Technology (NIST). He received a B.S. in Physics from Louisiana State University and a M.S. and Ph.D. in Physics from Cornell University. At Cornell he helped to build the first time-resolved high-resolution electron energy loss spectrometer for measuring surface-molecular vibrational excitations. At IBM as a postdoc, he did early scanning tunneling microscopy work that produced atomic-resolution images of Cl-modified Si surfaces, work published in Physical Review Letters and Science. At NIST he contributed to the Molecular Measuring Machine project, applied mathematical morphological methods to the tip-sample interaction in an STM or AFM to invent the first blind reconstruction method for determination of tip geometry (with over 400 citations at this writing the 4th most heavily cited paper in J. Res. NIST), and developed JMONSEL, a Monte Carlo simulator that uses a suite of physics models for electron-solid interactions to simulate secondary electron image formation for 3-dimensional samples of arbitrary shape. He is a fellow of the Washington Academy of Sciences, recipient of three Nyyssonen Metrology best paper awards, a Nanotech Briefs Nano50 Technology Award, and Dept. of Commerce Silver and Gold medals.

Publications

Probing Electrified Liquid-Solid Interfaces with Scanning Electron Microscopy

Author(s)
Hongxuan Guo, Alexander Yulaev, Evgheni Strelcov, Alexander Tselev, Christopher M. Arble, Andras Vladar, John S. Villarrubia, Andrei Kolmakov
The mean free path of secondary electrons in aqueous solutions is on the order of a nanometer, making them a suitable probe of ultrathin electrical double

On Low-Energy Tail Distortions in the Detector Response Function of X-Ray Microcalorimeter Spectrometers

Author(s)
Galen C. O'Neil, Paul Szypryt, Endre Takacs, Joseph N. Tan, Sean W. Buechele, Aung Naing, Young I. Joe, Daniel S. Swetz, Daniel R. Schmidt, William B. Doriese, Johnathon D. Gard, Carl D. Reintsema, Joel N. Ullom, John S. Villarrubia, Yuri Ralchenko
We use narrow spectral lines from the X-ray spectra of various highly charged ions to measure low-energy tail-like deviations from a Gaussian response function
Created October 9, 2019, Updated July 11, 2022