Department of Physics and Astronomy
University of South Carolina
712 Main Street
Columbia, South Carolina 29208
(803) 777-6407
For further information visit my homepage
N530003@univscvm.csd.sc.edu
Electron spin resonance studies of mixed crystals and glasses containing transition metal ions; ferroelectric and antiferomagnetic phase transitions. Monte Carlo and effective field calculations in magnetic systems. Low field absorption in high temperature super conductors.
Among the most active areas of research in condensed matter physics are critical phenomena, domain growth far from equilibrium, and high temperature superconductors. These problems are addressed in our experimental program on the magnetic properties of superconductors and their relationship to Josephson junctions and equilibrium and dynamical properties of ferroelectrics.
Using novel electron paramagnetic resonance (EPR) techniques developed by our group, the microscopic details of the polarization in KDP (potassium dihydrogen phosphate) type ferroelectrics are studied. In particular, the EPR method provides information about the rate of nucleation on the growth of ferroelectric domains and on the dynamics of electric field switching. Using a homemade EPR spectrometer we are studying microwave absorption at zero and low magnetic field of high temperature superconductors. The processes of fluxon entry, motion, and pinning are being clarified.
In addition to my work in EPR, I am involved in Monte Carlo numerical simulations of equilibrium critical phenomena and non-equilibrium processes such as domain nucleation and growth. Recent studies have focused on the properties of random dilute magnetic systems with frustration, renormalization group and finite-size scaling analysis of Ising and Heisenberg lattices, and domain formation and growth in randomly dilute frustrated systems in three dimensions. A new attached array processor has boosted our computation power by more than an order of magnitude.
For further information visit Condensed Matter Physics.
"Stability Study of Lecithin Liposomes During Storage Using ESR, "
A.A. Hager, T. De Paoli, J.E. Ihlo, H.A. Farach, C.P. Poole, Jr., Spectrochimica Acta, 49A, 1999, (1993).
"Study of Order and Dynamics in Lecithin Liposomes with High Cholesterol Content, "
R. Costanzo, A.A. Hager, T. De Paoli, J.E. Ihlo, H.A. Farach, C.P. Poole, Jr., Spectrochimica Acta, 50A, 203 (1993).
"Switching Times of Domains in DKDP, "
O.A. Lopez, H.A. Farach, C.P. Poole, Jr., R.J. Creswick, Ferroelectrics144, 119 (1993).
"Equilibrium Domain Configuration of KDP-Type Ferroelectrics, "
J.M. Knight, H.A. Farach, C.P. Poole, Jr., Ferroelectrics, 157, 51 (1994).
"A Numerical Study of Vortex Interactions for High Temperature Superconductors, "
S. Aktas, C.P. Poole, Jr., and H.A. Farach, J. Phys. Condens. Matter, 6, 7373 (1994).
"Measurement of Flux Creep in Bi2Sr2CaCu2O8 Using Electron Spin Resonance, "
M. Pencarinha, C. P. Poole, Jr., H.A. Farach, Journal of Physics and Chemical Solids, 56, 301 (1995).
"Membrane Fluidity and t-BOOH Initiated oxidative Stress in Erythrocytes from Patients with Haemolytic Uraemic
Syndrome, "
G. Facorro, F. Aguirre, L. Florentin, M. Diaz, T. De Paoli, J. Ihlo, A. Hager, JY. Sanchez Avalos, H.A. Farach, C.P. Poole, Jr., submitted to
Pediatric Neurology.
"Fluxon Model of Low-Field Absorption in Granular Type-II Superconductors, "
H.A. Farach, R.J. Creswick, C.P. Poole, Jr., O.A. Lopez, submitted to Physical Review.
"Glutathione Decay in Stored Blood Measured by Electron Spin Resonance, "
A.K. Goroncy, H.A. Farach, C.P. Poole, Jr., F. Gonzalez, accepted for publication in Journal of Biological Systems.
by Richard Hoskins
and copyright © 1998, The
Board of Trustees of the University of South Carolina.
URL
http://boson.physics.sc.edu/~physmgr/FacultyStaff/Brfarach.html