1. Dr. A. R. Koymen New Physics in Magnetic Nanolayers
Sputtering System
SQUID

2. Artificial Ferrimagnets & Compensation Temperature→ H

3. Thermal Hysteresis (Bow-tie) Magnetic Superheating and Supercooling
S. Demirtas, M. R. Hossu, R. E. Camley, H. C. Mireles and A. R. Koymen, accepted for publication in
Phys. Rev. B

4. TM and RE response to temperature
Different response of the sublattices to temperature is
the key for thermal hysteresis

5. Thermal Hysteresis vs Hext
Experiment
Theory
[Co 2nm/Gd 2nm]8

6. Co/Tb Multilayer Maria Hossu and A. R
Co/Tb Multilayer Maria Hossu and A. R. Koymen, accepted for publication in Journal of Applied Physics

7. CoGd Alloys (experiment vs theory) S. Demirtas, R. Camley and A. R
CoGd Alloys (experiment vs theory) S. Demirtas, R. Camley and A. R. Koymen, accepted for publication in Applied Physics Letters

8. Magnetic Recording (toy model)
Positive magnetic field
Selective
(writes one type of data)
Symmetric and tunable
Amorphous
Fe, Co, Gd, Tb
(perpendicular/longitudinal)
Stable at small sizes (AF coupled)
High areal density
Grain size? seed layer?

9. Ongoing Research Maria Hossu(Ph.D. student)
Manufacture multilayers that have out of plane anisotropy (use new X-ray machine)
Mustafa Arikan (Ph.D. student)
Discover new magnetic semiconductors for device applications (GaTbAs, GaGdAs)

10. Interface domains
Switching of the hard layers creates interface domains
Hard-soft change relaxes interface domains

11. Multiple thermal hysteresis – Co/Gd
Decoupling of the hysteresis
loop can create
tunable thermal hysteresis