Shell model lattice dynamics of transition metal oxides

Upadhyaya, K. S.; Singh, R. K.

doi:10.1016/s0022-3697(74)80137-x

Cited by 27 publications

(9 citation statements)

References 14 publications

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“…Indeed, a weak multiphonon structure close to 400 cm −1 has been calculated by Upadhyaya and Singh. 52 However, much stronger peaks in the combined density of states are calculated to appear close to 435, 500, and 535 cm −1 , which could not be identified unambiguously. In addition, it has to be stated that the temperature dependence of the observed structures ͓inset ͑b͒ of Fig.…”

Section: Resultsmentioning

confidence: 92%

Optical spectroscopy in CoO: Phononic, electric, and magnetic excitation spectrum within the charge-transfer gap

et al. 2008

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The reflectivity of single-crystalline CoO has been studied by optical spectroscopy for wave numbers ranging from 100 to 28 000 cm −1 and for temperatures 8 Ͻ T Ͻ 325 K. A splitting of the cubic IR-active phonon mode on passing the antiferromagnetic phase transition at T N = 289 K has been observed. At low temperatures the splitting amounts to 15.0 cm −1 . In addition, we studied the splitting of the cubic crystal-field ground state of the Co 2+ ions due to spin-orbit coupling, a tetragonal crystal field, and exchange interaction. Below T N , magnetic-dipole transitions between the exchange-split levels are identified, and the energy-level scheme can be well described with a spin-orbit coupling = 151.1 cm −1 , an exchange constant J = 17.5 cm −1 , and a tetragonal crystal-field parameter D = −47.8 cm −1 . Already in the paramagnetic state electric-quadrupole transitions between the spin-orbit split level have been observed. At high frequencies, two electronic levels of the crystal-field-split d manifold were identified at 8 000 and 18 500 cm −1 .

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Section: Resultsmentioning

confidence: 92%

Optical spectroscopy in CoO: Phononic, electric, and magnetic excitation spectrum within the charge-transfer gap

et al. 2008

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“…[18] or 500 cm −1 in Ref. [19]. The highest frequency band at 1050 cm −1 has complex origin: it envelops two bands related to the TO + LO (a band wing at 950 cm −1 ) and 2LO modes.…”

Section: Resultsmentioning

confidence: 92%

Raman and infrared spectromicroscopy of manganese oxides

Миронова-Улмане

Kuzmin

Grūbe

2009

Journal of Alloys and Compounds

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“…The last four parameters are determined by the knowledge of electrical polarizability (α 1 , α 2 ) and the zone center optical vibration frequencies (ω L , ω T ) given by eqs. (8), (9), (11), and…”

Section: Both Ions Polarizable Model (Bipm)mentioning

confidence: 99%

“…The strange features in the nature and physical properties of TMO in the paramagnetic phase (NaCl Structure) has given an increased interest in the study of their lattice dynamics. The lattice dynamics of MnO, CoO and NiO has been studied in detail by many experimental [7][8][9][10] and theoretical workers [11][12][13][14] with great success. While such studies for FeO (wustite) 15) has met only with moderate success.…”

Section: §1 Introductionmentioning

confidence: 99%

Lattice Dynamics of Transition Metal Oxides-An Application to FeO in the Paramagnetic Phase

Upadhyaya¹,

Upadhyaya²,

Yadav³

2001

J. Phys. Soc. Jpn.

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The basic equations of three-body force shell model have been corrected for the ionic charge parameter Z. This correction also modifies the expressions for the shell and core charge parameters. Our model has been applied to study the phonon dispersion curves, Debye temperatures variation, combined density of states and two-phonon Raman scattering spectra of wustite. This approach has been found successful in interpreting the complete lattice dynamics of FeO only when both the ions are considered to be polarizable. There is good scope for the fresh determination of positive ion polarizability and Debye temperatures variation. It is concluded that the presence of magnetic and anharmonic interactions have no effect on the lattice dynamics of FeO in its paramagnetic phase.

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Shell model lattice dynamics of transition metal oxides

Cited by 27 publications

References 14 publications

Optical spectroscopy in CoO: Phononic, electric, and magnetic excitation spectrum within the charge-transfer gap

Optical spectroscopy in CoO: Phononic, electric, and magnetic excitation spectrum within the charge-transfer gap

Raman and infrared spectromicroscopy of manganese oxides

Lattice Dynamics of Transition Metal Oxides-An Application to FeO in the Paramagnetic Phase

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