Electron spin resonance measurements of the spin Hamiltonian zero‐field splitting parameterDas a function of temperature for trigonally distorted Cr3+⋅6H2O magnetic complexes in families of hydrated crystals. I

1975 ◽  
Vol 63 (10) ◽  
pp. 4450-4455 ◽  
Author(s):  
A. Manoogian ◽  
A. Leclerc
1966 ◽  
Vol 44 (11) ◽  
pp. 2749-2755 ◽  
Author(s):  
N. E. Hedgecock ◽  
S. C. Chakravartty

ESR spectra of Fe+3 located at one of the aluminium sites in cordierite have been investigated at X- and K-band frequencies at room temperature. The spectra exhibit large zero-field splitting and have been fitted to a spin Hamiltonian of orthorhombic symmetry, having constants b20 = 14.6 ± 0.1 kG, b22 = 8.5 ± 0.1 kG, and isotropic g = 2.004 ± 0.002.


1976 ◽  
Vol 54 (2) ◽  
pp. 217-222 ◽  
Author(s):  
K. Pack ◽  
A. Manoogian

The electron-nuclear double resonance (ENDOR) of 53Cr3+ ions and the electron spin resonance (ESR) of VO2+ ions are studied in single crystals of AlCl3∙6H2O. The ENDOR measurements are done at 4.2 K while the resonance of VO2+ is studied at room temperature. The sign of the Cr3+ spin Hamiltonian zero field splitting parameter D is found to be negative while the anisotropic hyperfine parameter has the relation A < B. It is concluded that the octahedron of waters surrounding the chromium ion is trigonally compressed. The value of the 53Cr3+ quadrupole interaction parameter Q′ is nearly the same as that found previously in the cesium alums even though the D value is considerably smaller in AlCl3∙6H2O. This indicates that Q′ is independent of D at 4.2 K in these salts and the expected proportionality [Formula: see text], which is based on a purely static distortion for the octahedron of waters surrounding the Cr3+ ion, does not hold. The resonance results for VO2+ show the nature of the two inequivalent but otherwise similar Al∙6H2O complexes in the unit cell. The VO2+∙5H2O complexes associated with the two types of aluminum sites are found to be rotated relative to each other by an angle of 33 ± 3° in the plane perpendicular to the crystal c axis. A comparison of the spin Hamiltonian parameters of VO2+ and 53Cr3+ in AlCl3∙6H2O with those obtained previously in CsAl alum indicates that the Al∙6H2O complexes in CsAl alum are more susceptible to distortion upon impurity doping than are those in AlCl3∙6H2O.


2003 ◽  
Vol 58 (5-6) ◽  
pp. 303-305 ◽  
Author(s):  
V. K. Jain

The electron spin resonance (ESR) of Cr3+ in K1−xTlxAl(SO4)2·12H2O has been studied at 300 K and 9.45 GHz. The ESR spectrum for x between 30 and 90% shows several chromium complexes. The variation of the zero-field splitting parameter D suggests that monovalent ions play an important role in the trigonal distortion of the water octahedron around the trivalent metal ion in alums. - PASC: 76.30 F.


1977 ◽  
Vol 55 (14) ◽  
pp. 2728-2731 ◽  
Author(s):  
D. R. Arnold ◽  
J. R. Bolton ◽  
G. E. Palmer ◽  
K. V. Prabhu

The phosphorescence emission and electron spin resonance spectra of methyl mesitoate (1) and mesitonitrile (2) have been studied in order to assess the steric effect (inhibition of resonance) in the former. The triplet energy of 1 (80.5 kcal mol−1) is considerably higher than that of 2 (74.2 kcal mol−1) while the zero-field splitting parameters are very similar (1, D/hc = 0.127 cm−1, E/hc = 0.013 cm−1; 2, D/hc = 0.127 cm−1, E/hc = 0.006 cm−1). The triplet energy and zero-field splitting parameters of o-, m-, and p-methyl toluate and o-, m-, and p-tolunitrile are also reported.


2003 ◽  
Vol 58 (12) ◽  
pp. 677-681
Author(s):  
V. K. Jain

Electron spin resonance of Mn2+ doped in Eu2M”3 (NO3)12.24H2O (M” = Zn, Co) single crystals has been studied at 295 and 77 K using an X-band spectrometer. The observation of resolved Mn2+ spectra in Eu2Co3(NO3)12.24H2O at 295 K have been interpreted in terms of random modulation of interaction between Mn2+ and divalent cobalt ions by the rapid spin-lattice relaxation of cobalt ions. T1 of divalent cobalt has been estimated to be ∼ 5×10−12 s at 295 K. The superposition model is applied to the zero-field splitting parameter D.- PACS: 76.30 F


Sign in / Sign up

Export Citation Format

Share Document