Crystal field effect on EPR and optical absorption properties of natural green zoisite

Henry Javier-Ccallata, Shigueo Watanabe

Research output: Contribution to journalArticlepeer-review


In this study the electron paramagnetic resonance (EPR) and optical absorption (OA) of natural crystal of zoisite were investigated after γ (60Co) irradiation and high temperature annealing. EPR measurements show that the zoisite from Tefilo Otoni MG Brazil contain Cr3+, Fe3+ and Mn2+ ions and occupy distorted Al3+ octahedral and tetrahedral sites which are subjected to the action of a strong crystal field in axial direction. Absorption bands which in principle give rise to sets of EPR lines between 500 and 2500 G were found using the deconvolution method. The application of high doses of gamma ray and high temperature annealing has shown no significant effects on EPR and OA spectra. Spin-allowed, spin-forbidden and crystal field parameters were calculated for 3d3 configuration and interpreted using the spin Hamiltonian formalism containing axial and rhombic terms in low symmetries.

Original languageEnglish
Pages (from-to)505-511
Number of pages7
JournalSpectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
StatePublished - Mar 2013
Externally publishedYes

Bibliographical note

Funding Information:
We would like to thank Ms. E. Somesari and Mr. C. Gaia for kindly carrying out irradiation of the samples. This work was supported by CAPES and FAPESP.


  • Annealing
  • Crystal field
  • EPR
  • Optical absorption
  • Zoisite


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