Development of a Wideband EPR Spectrometer with Microstrip and Loop Antennas

  • Ponomaryov, A.N. (Department of Physics, Chung-Ang University) ;
  • Choi, K.Y. (Department of Physics, Chung-Ang University) ;
  • Suh, B.J. (Department of Physics, The Catholic University of Korea) ;
  • Jang, Z.H. (Department of Physics, Kookmin University)
  • Received : 2012.05.31
  • Accepted : 2012.08.24
  • Published : 2013.06.30


We have developed a new non-conventional electron paramagnetic resonance (EPR) spectrometer, in which no resonant cavity was used. We previously demonstrated a wide frequency range operation of an EPR spectrometer using two loop antennas, one for a microwave transmission and the other for signal detection [1]. In contrast to Ref. [1], the utilization of a microstrip antenna as a transmitter enhanced a capability of wide-band operation. The replacement of conventional capacitors with varactor diodes makes resonance condition easily reproducible without any mechanical action during tuning and matching procedure since the capacitance of the diodes is controlled electronically. The operation of the new EPR spectrometer was tested by measuring a signal of 1,1-diphenil-2-picrylhydrazyl (DPPH) sample in the frequency range of 0.8-2.5 GHz.


electron paramagnetic resonance;microstrip;varactor diode;microwave tuning and matching circuit


Supported by : NRF, KRF


  1. Z. H. Jang, B. J. Suh, M. Corti, L. Cattaneo, D. Hajny, F. Borsa, and M. Luban, Rev. Sci. Instrum. 79, 046101 (2008).
  2. A. Abragam and B. Bleany, Electron Paramagnetic Resonance of Transition Ions, Dover, New York (1986).
  3. Charles P. Poole Jr., Electron Spin Resonance: A Comprehensive Treatise on Experimental Techniques, Dover, New York (1997) p. 123-205.
  4. L. Bogani and W. Wernsdorfer, Nature Mater. 7, 179 (2008).
  5. V. V. Kostyuchenko and A. I. Popov, J. Exp. Theor. Phys. 107, 595 (2008).
  6. W. Wernsdorfer, M. Murugesu, and G. Christou, Phys. Rev. Lett. 96, 057208 (2006).
  7. W. Wernsdorfer, Nature Nanotechnology 4, 145 (2009).
  8. M. N. Leuenberger and D. Loss, Nature 410, 789 (2001).
  9. F. Meier, J. Levy, and D. Loss, Phys. Rev. Lett. 90, 047901 (2003).
  10. A. N. Ponomaryov, Namseok Kim, Jaewon Hwang, Hiroyuki Nojiri, Johan van Tol, Andrew Ozarowski, Jena Park, Zeehoon Jang, Byoungjin Suh, Sungho Yoon, and Kwang-Yong Choi, Chem. Asian J. 8, 1152 (2013).
  11. K. Y. Choi, Y. Matsuda, H. Nojiri, U. Kortz, F. Hussain, A. Stowe, C. Ramsey, and N. Dalal, Phys. Rev. Lett. 96, 107202 (2006).
  12. S. Muhlbauer, B. Binz, F. Jonietz, C. Pfleiderer, A. Rosch, A. Neubauer, R. Georgii, and P. Boni, Science 323, 915 (2009).
  13. C. C. Tsai, J. Choi, S. Cho, S. J. Lee, B. K. Sarma, C. Thompson, O. Chernyashevskyy, I. Nevirkovets, and J. B. Ketterson, Rev. Sci. Instrum. 80, 023904 (2009).
  14. V. P. Denysenkov and A. M. Grishin, Rev. Sci. Instrum. 74, 3400 (2003).
  15. C. D. Delfs and R. Bramley, J. Chem. Phys. 107, 8840 (1997).
  16. John H. Scofield, Am. J. Phys. 62, 129 (1994).
  17. N. D. Yordanov and A. Christva, Appl. Magn, Reson. 6, 341 (1994).