6) High Sensitive ESR and CR Measurements at High Magnetic Fields and Low Temperatures

In order to obtain information on magnetic excitations, magnetic structure and cyclotron effective masses, the high sensitive ESR and CR measurements system have been developed using a vector network analyzer, which is used at the frequency range between 30 to 190 GHz in the temperature range from 0.5 to 300 K and in magnetic fields up to 15 T by a superconducting magnet. In addition, we have successfully observed new ESR mode on low-dimensional quantum-spin material Cu-benzoate below 0.5 K using the equipment with a 3He-4He dilution refrigerator.

IMR, Tohoku University : Keiichi Koyama, Makoto Yoshida, Mitsuhiro Motokawa Okayama University : Hiroyuki Nojiri Akita University : Takuo Sakon Reference : K. Koyama, M. Yoshida, H. Nojiri, T. Sakon, D.X. Li, T. Suzuki, M. Motokawa, "Antiferromagnetic resonance and magnetic structure of GdAs ", J. Phys. Soc. Jpn., 69 (2000) 1521-1525.