Accession Number:

ADA470558

Title:

Injection and Scattering of Polarized Spins at Nanoscale Polymer Interfaces

Descriptive Note:

Final rept. 1 Jan 2002-31 May 2004

Corporate Author:

OHIO STATE UNIV COLUMBUS DEPT OF PHYSICS

Personal Author(s):

Report Date:

2004-05-31

Pagination or Media Count:

15.0

Abstract:

We made excellent progress several directions. We demonstrated that VTCNE2 is a room temperature fully spin polarized magnetic semiconductor of interest for spintronic applications, including spin valves. We increased the coercivity which is crucial for spintronics device of the parent material VTCNE2 by doping with ions that have large magnetocrystalline anisotropy Co, Fe, etc.. For Co and Fe substantially higher coercive fields, Hc, than the pure VTCNE2 275 Oe for x 0.3 and 1100 Oe for x 0.05 at 5 K, respectively were realized, while in case of Ni Hc does not exceed 14 Oe. Tc for the materials with x 0.3 exceeds 300 K. We extended MR measurements to very high magnetic fields up to 32 T to observe the remarkable linear MR behavior below the ordering temperature predicted for this magnetic semiconductor. Ferrimagnetic resonance FMR studies have been performed on VTCNE2 using high frequency microwaves 240 GHz to enhance the spectral resolution. Effective magnetization, Meff, intensity and linewidth behaviors of individual peaks indicate long-range magnetic ordering and also the presence of glassy nature due to the formation of multi-domains. XANES studies performed at ANL, show that vanadium ions are coordinated by 6 nitrogen atoms.

Subject Categories:

  • Organic Chemistry
  • Polymer Chemistry
  • Electrical and Electronic Equipment
  • Electricity and Magnetism
  • Industrial Chemistry and Chemical Processing

Distribution Statement:

APPROVED FOR PUBLIC RELEASE