title: Optical absorption and EPR studies on beaverite mineral.
abstract: The behaviour of transition metal ions in beaverite mineral has been studied by spectroscopic techniques such as electron paramagnetic resonance and absorption spectroscopy in the UV-vis and NIR regions. The ground state of Cu(II) ion in beaverite is confirmed as (2)B(1g) since g(parallel)>g(perpendicular) (2.42>2.097). A resonance noticed at g=2.017 is ascribed to Fe(III) impurity. Two sets of three characteristic bands observed in the optical absorption spectra are assigned to the same transitions, (2)B(1g)-->(2)A(1g), (2)B(1g)-->(2)B(2) and (2)B(1g)-->(2)E(g) of Cu(II) ion in tetragonal field. The presence of Fe(III) bands is supportive evidence for iron impurity in the mineral. Mid infrared spectrum is due to overtones and combination tones of water and hydroxyl groups.
authors.affiliation: Department of Physics, SVD College, Suryapet, Nalgonda District, India.
authors.forename: Md
authors.initials: M
authors.lastname: Fayazuddin
authors.forename: N C Gangi
authors.initials: NC
authors.lastname: Reddy
authors.forename: G Siva
authors.initials: GS
authors.lastname: Reddy
authors.forename: S Lakshmi
authors.initials: SL
authors.lastname: Reddy
authors.forename: P Sambasiva
authors.initials: PS
authors.lastname: Rao
authors.forename: R L
authors.initials: RL
authors.lastname: Frost
mesh_terms: D003300:Copper / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D008903:Minerals / Q000737:chemistry*; D055095:Optics and Photonics; D013056:Spectrophotometry, Ultraviolet; D019265:Spectroscopy, Near-Infrared; D013696:Temperature; D013816:Thermodynamics
chemical_list: D008903:Minerals; D003300:Copper