A study of the host lattice effect in the lanthanide hydroxides. 34 GHz Gd3+ impurity ion EPR spectra at 77 and 294 K

1982 ◽  
Vol 60 (11) ◽  
pp. 1573-1588 ◽  
Author(s):  
V. M. Malhotra ◽  
H. A. Buckmaster
Keyword(s):  
Point Charge ◽  
Ionic Radius ◽  
Host Lattice ◽  
Epr Spectra ◽  
Zero Field ◽  
Nearest Neighbour ◽  
Zero Field Splitting ◽  
Impurity Ions ◽  
Lattice Effect ◽  
Impurity Ion

The 34 GHz EPR spectra of 5-state (4f7, 8S) Gd3+ impurity ions (~1%) in the isostructural [Formula: see text] symmetry Ln(OH)3 host lattice (Ln ≡ La, Sm, Eu, Tb, Ho, Y) have been studied at 77 and 294 K. The expected seven line ΔM = ± 1 spectrum is observed for Ln = La, Eu, Ho, and Y whereas only a single broad transition is observed for Ln ≡ Sm and Tb. The observed values of the zero field splitting (ZFS) parameter B20 as well as the TZFS are found to be related linearly to (i) the ionic radius, (ii) the Ln–O1 distance, and (iii) the Ln–O2 distance where O1 and O2 are the nearest neighbour equatorial and apical oxygens. However, the slopes are opposite to that predicted by a point charge lattice model. This paper discusses (i) the SH parameters, (ii) the host lattice effect, (iii) the ZFS processes, and (iv) the linewidths observed in the Ln(OH)3 host lattice and attempts to explain the observations using the existing theory. It is found that this apparently simple host lattice exhibits complex effects which do not change systematically with the host lanthanide ion, unlike that observed in most other isostructural lanthanide hosts that have been studied using Gd3+ impurity ions.

Electron spin resonance of paramagnetic impurities in antiferromagnetic compounds

1991 ◽  
Vol 433 (1888) ◽  
pp. 461-468 ◽  
Keyword(s):  
Internal Field ◽  
Host Lattice ◽  
Nuclear Resonance ◽  
Dipolar Field ◽  
Exchange Field ◽  
Paramagnetic Impurities ◽  
Resonance Frequencies ◽  
Spin Resonance ◽  
Impurity Ions ◽  
Impurity Ion

The possibility of magnetic resonance measurements on an impurity in an antiferromagnetic host lattice is discussed. The ion is subject to an internal field B int ; consisting of B dip , the dipolar field generated by the antiferromagnetic moments of the host ions, that can be calculated, and an exchange field B E . For a simple two sublattice antiferromagnet, two resonance frequencies should be observed; equations for their angular dependence are given, including the effect of hyperfine interaction. Impurity ions with Kramers doublets are discussed, together with ions with singlet ground states, for which enhanced nuclear resonance should be possible. A number of simple antiferromagnetic compounds of lanthanide (4f) ions that order at liquid helium temperatures are mentioned briefly, but for simplicity, the discussion is concentrated on GdVO 4 as the host lattice. A formula, based on the known exchange field in the host lattice, is deduced for its effect on the impurity ion.

EPR of Gd3+ in Sulfate Host Crystals of Low Symmetry

1997 ◽  
Vol 52 (4) ◽  
pp. 323-330
Author(s):  
M. Bode ◽  
B. D. Mosel ◽  
W. Müller-Warmuth
Keyword(s):  
Metal Ion ◽  
Charge Compensation ◽  
Epr Spectra ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Paramagnetic Resonance ◽  
Spin Quantum ◽  
Spin Quantum Number ◽  
Host Metal ◽  
Low Symmetry

Abstract Electron paramagnetic resonance (EPR) spectra of trivalent gadolinium have been investigated in orthorhombic sulfate host crystals MeSO4 with Me = Sr, Ba, Cd, Hg, Pb and K2SO4 . Because of the low symmetry of the host crystals and the spin quantum number 7/2, complex spectra for several orientations of the magnetic field containing a large number of individual lines had to be analyzed. The spin Hamiltonian parameters have been rigorously determined from the rotational diagrams. Gd3+ has been found to substitute, first of all, for the monoclinic sites of the host metal ion with charge compensation at larger distances. To a small extent, charge compensation in the vicinity has also been observed, arising from additional centres and spectra with lower intensities. Correlations between EPR spectra and crystal structure are reflected in the values of the zero field splitting parameters.

EPR spectra and zero-field splitting of exchange-coupled copper(II)-manganese(II) pairs

1981 ◽  
Vol 20 (8) ◽  
pp. 2734-2735 ◽  
Author(s):  
L. Banci ◽  
A. Bencini ◽  
D. Gatteschi
Keyword(s):  
Epr Spectra ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Field Splitting

Magnetic interactions and single-ion zero-field-splitting effects in the two-sublattice manganese chain MnMn(EDTA).cntdot.9H2O: magnetism and single-crystal EPR spectra

1991 ◽  
Vol 30 (5) ◽  
pp. 947-950 ◽  
Author(s):  
J. J. Borras-Almenar ◽  
R. Burriel ◽  
Eugenio. Coronado ◽  
D. Gatteschi ◽  
C. J. Gomez-Garcia ◽  
...  
Keyword(s):  
Single Crystal ◽  
Magnetic Interactions ◽  
Epr Spectra ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Field Splitting

The Dimeric Structure of Bis(1,3-Dimethylcyclopentadienyl)titanium(III) Chloride

1996 ◽  
Vol 61 (9) ◽  
pp. 1285-1294 ◽  
Author(s):  
Karel Mach ◽  
Vojtech Varga ◽  
Günter Schmid ◽  
Jörg Hiller ◽  
Ulf Thewalt
Keyword(s):  
Crystal Structure ◽  
Triplet State ◽  
Structure Analysis ◽  
Crystal Structure Analysis ◽  
Epr Spectra ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Field Splitting ◽  
X Ray ◽  
Dimeric Structure

The X-ray crystal structure analysis of bis(1,3-dimethylcyclopentadienyl)titanium(III) chloride revealed that it is a centrosymmetric chlorine-bridged dimer [(η5-C5H3Me2)2Ti(μ-Cl)]2 (1) with the Ti-Ti distance of 3.9155(8) Å. Its skeleton is virtually identical with those of the [(η5-C5H5)2Ti(μ-Cl)]2 and [(η5-C5H4Me)2Ti(μ-Cl)]2 dimers. The solution EPR study proved that 1 remains a dimer in toluene whereas it dissociates in 2-methyltetrahydrofuran (MTHF) to give (η5-C5H3Me2)2TiCl . MTHF. The EPR spectra of frozen toluene solutions proved that 1 forms the triplet state whose g-tensor and zero-field splitting D are virtually the same as those of [(η5-C5H5)2Ti(μ-Cl)]2.

Magnetic resonance of lanthanide ions as magnetic probes in the antiferromagnetic phase of dysprosium phosphate

1991 ◽  
Vol 435 (1895) ◽  
pp. 605-614 ◽  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Moments ◽  
Internal Field ◽  
Host Lattice ◽  
Lanthanide Ions ◽  
Exchange Field ◽  
Impurity Ions ◽  
Isotropic Exchange ◽  
Impurity Ion ◽  
Magnetic Probes

Measurements of electron magnetic resonance are discussed for impurity ions in the antiferromagnetic host compound DyPO 4 (Néel temperature T N = 3.39 K). This is a simple two sublattice antiferromagnet; the impurity ions are Yb 3+ and Er 3+ , each with a Kramers doublet as the ground state. Resonance is observed at frequencies of ca . 24 and 34 GHz, and the angular dependence of the magnetic field is fitted to simple theoretical equations. Since the magnetic moments in the host lattice are ordered, the resonance lines are relatively narrow, making it possible to determine the value of the internal field acting on each impurity ion. From this, the exchange field is obtained by subtracting the value of the dipolar field generated by the ordered moments of the host ions. Some measurements have been made in the spin flop phase. The values of the exchange field are found not to conform to a simple model based on isotropic exchange interaction between the real electron spins of the lanthanide ions. Hyperfine splitting is detected from the odd isotope 171 Yb, natural abundance 14%, I = ½.

Importance of Fourth-Order Zero-Field Splitting Terms in Random-Orientation EPR Spectra of Eu(II)-Doped Strontium Aluminate

2003 ◽  
Vol 107 (51) ◽  
pp. 11539-11546 ◽  
Author(s):  
Hideto Matsuoka ◽  
Ko Furukawa ◽  
Kazunobu Sato ◽  
Daisuke Shiomi ◽  
Yoshitane Kojima ◽  
...  
Keyword(s):  
Fourth Order ◽  
Epr Spectra ◽  
Zero Field ◽  
Strontium Aluminate ◽  
Zero Field Splitting ◽  
Random Orientation ◽  
Order Zero ◽  
Field Splitting
Sign in / Sign up

Export Citation Format

Share Document