Alexana Roshko

Publications

Enhanced superconducting transition temperature in electroplated rhenium

April 30, 2018

Author(s):

David P. Pappas, Don David, Mustafa Bal, Ilke Arslan, Paul T. Blanchard, Ronald B. Goldfarb, Dustin A. Hite, Hsiang S. Ku, Russell E. Lake, Junling Long, Alexana Roshko, Lee D. Pappas, Britton L. Plourde, Jianguo Wen, Xian Wu, Corey Rae H. McRae

We show that electroplated Re ﬁlms in multilayers with noble metals such as Cu, Au, and Pd have an enhanced superconducting critical temperature...

Comparison of CBED and ABF Atomic Imaging for GaN Polarity Determination

November 08, 2016

Author(s):

Alexana Roshko, Matthew D. Brubaker, Paul T. Blanchard, Kristine A. Bertness, Todd E. Harvey, Igor Levin, R.H. Geiss

A comparison of two electron microscopy techniques used to determine the polarity of GaN nanowires is presented. The techniques are convergent beam electron...

Electron Enhanced Growth of Crystalline Gallium Nitride Thin Films at Room Temperature and 100 C Using Sequential Surface Reactions

July 01, 2016

Author(s):

Alexana Roshko, Jaclyn Sprenger, Andrew S. Cavanagh, Steven George, Huaxing Sun, Kathryn J. Wahl

Low energy electrons may provide mechanisms to enhance thin film growth at low temperatures. In this work, gallium nitride (GaN) films were deposited over...

Structural and optical nanoscale analysis of GaN core-shell microrod arrays fabricated by combined top-down and bottom-up process on Si (111)

May 15, 2016

Author(s):

Sergiy Krylyuk, Marcus Muller, Gordon Schmidt, Sebastian Metzner, Peter Veit, Frank Bertram, Ratan K. Debnath, Jong Yoon Ha, Baomei Wen, Paul T. Blanchard, Alexana Roshko, Abhishek Motayed, Matthew R. King, Albert Davydov, Jurgen Christen

Large arrays of GaN core-shell microrods were fabricated on Si(111) substrates applying a combined bottom-up and top-down approach which includes inductively...

Spontaneous growth of GaN nanowire nuclei on N- and Al-polar AlN: A piezoresponse force microscopy study of crystallographic polarity

March 02, 2016

Author(s):

Matthew D. Brubaker, Alexana Roshko, Paul T. Blanchard, Todd E. Harvey, Norman A. Sanford, Kristine A. Bertness

The polarity of gallium nitride (GaN) nanowire nuclei grown on AlN layers was studied by piezoresponse force microscopy (PFM). N- or Al-polar AlN layers were...