Dynamic response of exchange bias in graphene nanoribbons
Abstract
The dynamics of magnetic hysteresis, including the training effect and the field sweep rate dependence of the exchange bias, is experimentally investigated in exchange-coupled potassium split graphene nanoribbons (GNRs). We find that, at low field sweep rate, the pronounced absolute training effect is present over a large number of cycles. This is reflected in a gradual decrease of the exchange bias with the sequential field cycling. However, at high field sweep rate above 0.5 T/min, the training effect is not prominent. With the increase in field sweep rate, the average value of exchange bias field grows and is found to follow power-law behavior. The response of the exchange bias field to the field sweep rate variation is linked to the difference in the time it takes to perform a hysteresis loop measurement compared with the relaxation time of the anti-ferromagnetically aligned spins. The present results may broaden our current understanding of magnetism of GNRs and would be helpful in establishing the GNRs-based spintronic devices.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 01, 2012
- Source ID
- 10.1063/1.4755840
Entities
People
- J. M. Tour
- J. Vanacken
- S. Narayana Jammalamadaka
- Sohail Rao
- V. V. Moshchalkov
- Wei Lu
Organizations
- Air Force Office of Scientific Research
- Indian Institute of Technology Hyderabad
- Katholieke Universiteit Leuven
- North Carolina State University
- Office of Naval Research
- Rice University
- United States Army Research Laboratory