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1.
The optical absorption spectrum of Ni2+ ion doped in ammonium zinc sulphate has been studied at room and liquid air temperatures. From the nature and the positions of the bands a successful interpretation of all the bands could be made assumingO h symmetry for the Ni2+ ion in the crystal. The fine splitting of the3 T 1 1 band at liquid air temperature has been successfully interpreted to be due to spin-orbit interaction. The crystal field and spin-orbit parameters derived areDq=1000 cm−1;B=750 cm−1;C=3.45B andξ=600 cm−1.  相似文献   

2.
Single crystals of nickel-doped sodium potassium sulphate were grown by slow evaporation method at room temperature. From the nature and position of the bands observed, a successful interpretation of all the observed bands could be made assuming the octahedral symmetry for the Ni2 + ion in the crystal. The bands have been ascribed to transitions from the ground3A2g(F) state to the excited3T2g(F),1Eg(D),3T1g(F),1T2g(D) and3T1g(P) states. The experimental and calculated energies are in good agreement. The crystal field parameters derived areDq= =880 cm–1,B= 900cm–1 andC=3600 cm–1.One of the authors, Sujatha John expresses her thanks to the Secretary and the Principal, R. B. V. R. Reddy College, Hyderabad for according her permission to pursue the M. Phil. course.  相似文献   

3.
Optical absorption spectrum of Cr3+ ion doped in zinc cesium sulphate hexahydrate single crystal has been studied both at room and liquid nitrogen temperatures. From the nature and position of the bands a successful interpretation of all the bands could be made assuming octahedral symmetry for the Cr3+ ion in the crystal. The observed bands are assigned to the transitions from the ground 4A2g(F) state to the excited 2Eg(G), 2T1g(G), 4T2g(F) and 4T1g(F) states.The crystal field parameters Dq = 1735 cm?1, B = 635 cm?1 and C = 4.75 B are found to give a good fit to the observed band positions.  相似文献   

4.
Optical absorption spectrum of chromium doped rubidium aluminium sulphate dodecahydrate single crystal is investigated. The electronic spectrum in the UV-VIS region is characteristic of Cr 3+ in trigonal symmetry and vibrational spectrum in the i.r. region is ascribed to the SO 42− and H 2O groups. The following crystal field parameters are evaluated for Cr 3+ in trigonal symmetry.Dq = 1840cm −1, Dσ = 140cm −1, Dτ = 140cm −1, B = 700cm −1 C = 3100cm −1.  相似文献   

5.
Single crystals of cobalt — doped ammonium perchlorate were grown at room temperature. The electronic absorption bands observed at room and liquid air temperatures have been assigned transitions from the ground4T1(F) state to the excited4T2(F),4A2(F),2T1(G) and4T1(P) states. The crystal parameters derived areDq=880 cm–1,B=865 cm–1 andC= 4·63B.The authors wish to express their thanks to the authorities of the Indian Institute of Science, Bangalore for kind permission to use their spectrophotometer. Two of the authors (B. C. V.Reddy and J. L.Rao) express their greatful thanks to the council of scientific and Industrial Research (New Delhi) for financial assistance.  相似文献   

6.
Single crystals of nickel-doped lithium potassium sulphate were grown by slow evaporation method at room temperature. From the nature and position of the bands observed, a successful interpretation of all the bands could be made assumingO h symmetry for the Ni2+ ion in the crystal. The bands have been assigned transitions from the ground3A2g(F) state to the excited3T2g(F),1Eg(D),3T1g(F),1T2g(D) and3T1g(P) states. The crystal field parameters derived areDq=910cm–1,B=890cm–1 andC=3560cm–1.The authors wish to express their thanks to Prof. K. Sreerama Murthy for his constant encouragement throughout this investigation. The authors are also thankful to Prof. Mihir Chowdhury, Indian Association for the cultivation of Science, Calcutta for giving permission to take the spectra.  相似文献   

7.
The He+He+1 interactions have been studied, as a function of the internuclear separation R, in terms of the electronic forces acting on the nuclei and the change in the charge distribution. The analysis reveals that at large R the atomic densities are polarized inwards, causing an attractive force on each nucleus, while at small R the difference in the nature of the interactions in the 2Σu and 2Σg systems is noted. It is seen that the He+He+1 (2Σu) interaction is less attractive than the He+1+He+1 interaction at lower values of R.  相似文献   

8.
B J Reddy  L Rama Moorthy 《Pramana》1982,19(5):449-454
Two sharp line-like bands calledN andR lines on the red side, a close doublet (B lines) on the violet side and two broad bands are observed for natural ruby. At liquid air temperature the splitting ofR line was found and also three sharp-bands calledR, R′ andB lines are identified with spin-forbidden transitions of2 E,2 T 1 and2 T 2. The two broad bands calledU band andY band are assigned accordingly to the spin-allowed transitions4 T 2 and4 T 1 respectively. The observed bands of natural ruby have been attributed to Cr3+ ion in an octahedral environment with trigonal distortion. The crystal field parameters which gave a good fit to the observed band positions areB=732 cm−1,C=4.25B,Dq=1830 cm−1,V=−1996 cm−1 andλ=34 cm−1.  相似文献   

9.
王雪俊  夏海平 《光学技术》2007,33(5):684-687
高温熔融法制备了69.5B2O3-20Li2O-(10-χ)CaO-χPbO-0.5Nd2O3(χ=1,3,5,7,mol%)和68.5Li2O-(29-φ)CaO-φAl2O3-2La2O3-0.5Nd2O3(φ=3,7,10,15,mol%)玻璃,测量了玻璃样品的吸收和发射光谱(800nm激光二极管激发),从吸收光谱出发,应用Judd-Ofelt理论获得了Nd3+光学跃起的强度参数。根据强度参数和发射光谱,计算了Nd3+离子4F3/2→4I11/2跃迁的荧光发射截面σe。结果显示,在B2O3-Li2O-CaO-PbO-Nd2O3系统中随着CaO的减少和PbO的增加,Nd3+离子的强度参数Ω2增大,表明样品的对称性降低;强度参数Ω6也增大,说明玻璃样品中Nd-O键的共价性和键强降低;同时,Nd3+离子4F3/2→4I11/2跃迁的荧光发射截面σe的大小和荧光强度都减小。在Li2O-CaO-Al2O3-La2O3-Nd2O3系统中,随着CaO的减少和Al2O3的增加,Nd3+离子的强度参数Ω2减小,说明样品的对称性增加;强度参数Ω6减小,说明玻璃样品中Nd-O键的共价性和键强增强;同时,Nd3+离子4F3/2→4I11/2跃迁的荧光发射截面的大小和荧光强度也都减小。  相似文献   

10.
Single srystals of calcium tartrate doped with VO2+ are grown from silica gel. Its optical absorption spectrum is studied at laboratory and liquid air temperatures. The spectrum is analysed and ascribed to VO2+ ion in C4v symmetry. The following crystal field parameters are evaluated.
Dq = 1835 cm?1, Ds = ?1980 cm?1, Dt = 1280 cm?1
  相似文献   

11.
Published in Zhurnal Prikladnoi Spektroskopii, Vol. 62, No. 4, pp. 30–37, July–August, 1995.  相似文献   

12.
The absorption spectrum of Mn2+ doped in diglycine barium chloride monohydrate has been studied at room temperature. The observed bands are assigned as transitions from the 6A1g(S) ground state to various excited quartet levels of a Mn2+ ion in a cubic crystalline field. A new method has been suggested to evaluate the Racah parameters (B and C) accurately. The observed band positions are fitted with four parameters B, C, Dq and α, and the values obtained for the parameters are B= 810 cm-1, C = 2990 cm-1, Dq = 750 cm-1 and α = 76 cm-1.  相似文献   

13.
Summary Substitutional Co2+ and Mn2+ ions at the two different Cd sites in the compound CsCdCl3 have been studied by using electron paramagnetic resonance. The preferential occupation, Co2+ in the CdII site, Mn2+ in the CdI site, is discussed in terms of crystallochemical symmetry arguments. Paper presented at the ?V International Conference on Ternary and Multinary Compounds?, held in Cagliari, September 14–16, 1982.  相似文献   

14.
Results of the optical absorption spectrum of VO2+ ion doped in caesium cadmium sulphate hexahydrate studied at room (300 K) and liquid nitrogen (77 K) temperatures are reported. The site symmetry of the ion is found to be C. Correlating the optical and ESR spectral data, the molecular orbital coefficients are evaluated.  相似文献   

15.
The possibility of obtaining laser action from Mn2+ doped glass has been investigated. The excited state absorption at the expected laser wavelength was measured and explains the unsuccessful attempts to obtain laser action.  相似文献   

16.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 53, No. 5, pp. 767–770, November, 1990.  相似文献   

17.
The reflectivity of KCl has been measured up to 45 eV with synchrotron radiation extending the range of previous measurements. The absorption coefficient is compared with an ab initio calculation using an orthogonalized-plane-wave expansion for the final states of the excited electron and including excitonic and crystalline effects. The distribution of the oscillator strength and its modulations are well reproduced by the theory.  相似文献   

18.
Abstract

Optical absorption spectrum of cobalt doped MgNH4PO4 · 6H2O (struvite) is investigated in UV-VIS-NIR regions. The spectrum in UV-VIS-NIR region is attributed to Co2+ in octahedral symmetry whereas the IR spectrum is attributed to vibrations due to PO4 3-, NH4 + and H2O. The following crystal field (Dq) and interelectronic repulsion (B, C) parameters are evaluated: Dq = 940cm?1, B = 870cm?1 and C = 3970cm?1.  相似文献   

19.
We recorded and rotationally analyzed a new emission band at 2563 Å obtained from a low-pressure, hot cathode and magnetically confined electric discharge through pure NO vapor. The available experimental data from photoion-fluorescence photon coincidence and translational energy loss spectroscopy, in conjunction with ab initio calculation, allowed assignment of the new band to the B2Σ+-X2Σ+ (0, 0) transition of the NO2+ ion.  相似文献   

20.
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