EPR, optical and superposition model study of Mn²⁺ doped L+ glutamic acid

Abstract

Electron paramagnetic resonance (EPR) study of Mn²⁺ doped L+ glutamic acid single crystal is done at room temperature. Four interstitial sites are observed and the spin Hamiltonian parameters are calculated with the help of large number of resonant lines for various angular positions of external magnetic field. The optical absorption study is also done at room temperature. The energy values for different orbital levels are calculated, and observed bands are assigned as transitions from ⁶A_1g(s) ground state to various excited states. With the help of these assigned bands, Racah inter–electronic repulsion parameters B = 869 cm⁻¹, C = 2080 cm⁻¹ and cubic crystal field splitting parameter Dq = 730 cm⁻¹ are calculated. Zero field splitting (ZFS) parameters D and E are calculated by the perturbation formulae and crystal field parameters obtained using superposition model. The calculated values of ZFS parameters are in good agreement with the experimental values obtained by EPR.

Keywords:

• organic compounds
• crystal growth
• crystal fields
• electron paramagnetic resonance
• optical properties

PACS No:

• 76.30.Da
• 76.30.Fc
• 71.70.Ch

Acknowledgements

The authors are thankful to the Head, SAIF, IIT Mumbai, Powai, Mumbai for providing the facility of EPR spectrometer. One of the authors, Manju Singh is thankful to the Head, Department of Physics, University of Allahabad, Allahabad for providing departmental facilities.

Disclosure statement

No potential conflict of interest was reported by the authors.