Condensed Matter Physics
Emeritus Status August 1, 2014
B.S., North Dakota State, 1962
A.M., Dartmouth College, 1964
Ph.D., Rice University, 1967
E-mail: blackstd (at) nd (dot) edu
Address: Nieuwland Science Hall 340a
The objective of the program directed by Prof. Blackstead is to discover new high temperature superconductors and to develop electronic device applications using these materials. Currently, we are studying materials in the class A2LnRu1-uSr2CuuO6 where A is an alkaline earth, Sr or Ba, and Ln is a lanthanide or Y. These materials are very attractive, since they are doped with a metal ion, not oxygen, and have (near) cubic symmetry. The superconducting transition temperatures are as high as 89K. We are growing crystals of these materials using a recently acquired traveling solvent floating zone (TSFZ) system, and we are experimenting with different doping strategies. Our measurement capability includes: resistivity, magnetization, and microwave frequency (5-80 GHz) surface resistance, as functions of temperature and applied magnetic (0-7T) field. Additionally, we have a femto-second laser system for the study of carrier dynamics. With collaborators, we carry out additional studies including: muon spin rotation, neutron diffraction, Mössbauer, and specific heat measurements.
“Anomalous magnetic ordering in PrBa2Cu4O8 and CmBa2Cu3O7,” H.A. Blackstead, M.P. Smylie, W.B. Yelon, Q. Cai, and M. Kahveci, Phys. Rev. B 77, 014436 (2008) (5 pages).
“The decomposition of YBa2Cu3O7-d doped into Ba2YRuO6,” H.A. Blackstead, W.B. Yelon, M. Kornecki, M.P. Smylie, P.J. McGinn, J.B. Yang, W.J. James, and Q. Cai, J. App. Phys. 103, 033904 (2008) (7 pages).
“A search for superconducting impurity phases in cubic Ba2GdRu1-uCuuO6,” H.A. Blackstead, M. Kornecki, M.P. Smylie, P.J. McGinn, W.B. Yelon, and Q. Cai, J. Alloys and Compounds 466 (2008) 31-38.
“Comment on ‘Origin of the superconductivity in the Y-Sr-Ru-O and Y-Sr-Cu-O systems’,” H.A. Blackstead, P.J. McGinn, M.P. Smylie, W.B. Yelon, J.B. Yang, and W.J. James, Phys. Rev. B 79, 016501 (2009).
“Antiferromagnetism and superconductivity: Determination of the Cu spin-spin relaxation time T2 and the spin-lattice relaxation time T1 in Gd1.5Ce0.5Sr2Cu2RuO10“, by H.A. Blackstead, W.B. Yelon, and M.P. Smylie, Solid State Communications 149, 39-40, pp. 1702-1705 (2009).
Full Curriculum Vitae (pdf)