Covalency in cubic lanthanide sesquioxides

Angelov, B.

doi:10.1088/0022-3719/10/18/002

Cited by 9 publications

(5 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Angelov [17] [14], Er [19] where the ionic radius of Fe 3+ is 3 pm longer than that of Co 3+ . 1) Tb (1) Symmetry operators (1)ÀX+1,Y,Z (2)ÀX+1,Y,ÀZ+1/2 (3)X,Y,ÀZ+1/2 (4)ÀX+1,ÀY+1,ÀZ+1 (5)X,ÀY+1,ÀZ+1 (6)ÀX+1/2,Y+1/2À1,Z (7)ÀX+1/2,Y+1/2,Z Ln ¼ Tb) is much longer than the 209.1 pm reported for the Lu-N bond in a lutetium imido complex [20].…”

Section: Symmetry Operatorsmentioning

confidence: 98%

Crystallographic and infrared spectroscopic study of bond distances in Ln[Fe(CN)6]·4H2O (Ln=lanthanide)

Zhou¹,

Wong²,

Faucher³

et al. 2008

Journal of Solid State Chemistry

View full text Add to dashboard Cite

Section: Symmetry Operatorsmentioning

confidence: 98%

Crystallographic and infrared spectroscopic study of bond distances in Ln[Fe(CN)6]·4H2O (Ln=lanthanide)

Zhou¹,

Wong²,

Faucher³

et al. 2008

Journal of Solid State Chemistry

View full text Add to dashboard Cite

“…This small mixture evidences the ionic nature of the Sc-O bond in agreement with the picture of scandium sesquioxide as an ionic insulator with some degree of covalent bonding between Sc and O atoms. 54 Above the Fermi level, the conduction band is predominantly Sc 3d with an admixture of O 2p states.…”

Section: Figures 2͑a͒ and 2͑b͒mentioning

confidence: 99%

“…54 In the case of mainly ionic compounds, the simplest and most widely used approximation for the calculation of the EFG at a probe atom is the point-charge model ͑PCM͒. 16 In this approximation, the EFG tensor at the probe site is given by V ii PCM = ͑1 − ␥ ϱ ͒V ii latt , where V ii latt is the EFG tensor originating from the nominal-valence point charges located at the ion positions in the lattice and ␥ ϱ is the Sternheimer antishielding factor, 16 which depends only on the probe.…”

Section: Comparison With Other Calculationsmentioning

confidence: 99%

Electronic and structural properties, and hyperfine interactions at Sc sites in the semiconductorSc2O3: TDPAC andab initiostudy

et al. 2010

View full text Add to dashboard Cite

The time-differential ␥-␥ perturbed-angular-correlation ͑TDPAC͒ technique using 44 Ti → 44 Sc tracers was applied to study the nuclear quadrupole interaction of the first excited I = 1 state of 44 Sc in the cubic bixbyite structure of scandium sesquioxide ͑Sc 2 O 3 ͒. In addition, ab initio calculations of electronic and structural properties and hyperfine parameters at the cationic sites of the Sc 2 O 3 structure were performed using the full-potential augmented plane wave plus local-orbital ͑APW+ lo͒ method. The accuracy of the calculations and the excellent agreement of the predicted electric-field-gradient ͑EFG͒ tensors and the structural properties ͑lattice parameters, internal positions͒ with the experimental results enable us to identify the observed hyperfine interactions and to infer the EFG sign that cannot be measured in conventional TDPAC experiments. Additionally, the APW+ lo calculations show that the EFG at Sc sites is originated in the population of Sc 3p states and give an explanation for the preferential occupation of the asymmetric cationic site C of the structure by the 44 Ti doping impurities. Finally, the validity of the ionic model, usually used to describe the EFG at native cation sites, is discussed.

show abstract

“…It is well known that the bonding in these sesquioxides is mainly ionic [20]. Under such conditions, the PCM [2,12] should be a good starting model to evaluate the EFG parameters at the two sites C and D. Using the lattice parameters and the atomic coordinates coming from the most accurate X-ray determinations quoted in the literature [21] and γ ∞ = −61.42 [22], the results of the PCM calculation (using a sphere radius of 20 nm) for both sites in Er…”

Section: The Bixbyite Structure Consequences On the Efg's And Point C...mentioning

confidence: 99%

Hyperfine interactions at 181 Hf ( Ta ) impurities implanted in Er 2 O 3 and Gd 2 O 3 : structural and electronic dependence of the EFG in bixbyite sesquioxides

et al. 2001

View full text Add to dashboard Cite

The time-differential-perturbed γ-γ angular-correlation technique (TDPAC) with ion-implanted 181 Hf tracers has been applied to study the hyperfine interactions of 181 Ta impurities in the cubic bixbyite structure of Er2O3 and Gd2O3. The TDPAC experiments were performed in air in the temperature range 300-1073 K (in the case of Er2O3) and 300-1173 K (in the case of Gd2O3). Three electrical-quadrupole interactions were found in each oxide in the whole studied temperature range. Two of them were attributed to the electric-field gradients (EFG) acting on 181 Ta probes substitutionally located on the two nonequivalent free-of-defects cation sites of the bixbyite structure. The EFG results are compared with predictions of the point-charge model and discussed together with previous results obtained with the probes 111 Cd and 181 Ta in other isomorphous sesquioxides. The temperature dependence of the hyperfine parameters for both oxides is also discussed in terms of dilatometric expansion data.

show abstract

Covalency in cubic lanthanide sesquioxides

Cited by 9 publications

References 17 publications

Crystallographic and infrared spectroscopic study of bond distances in Ln[Fe(CN)6]·4H2O (Ln=lanthanide)

Crystallographic and infrared spectroscopic study of bond distances in Ln[Fe(CN)6]·4H2O (Ln=lanthanide)

Electronic and structural properties, and hyperfine interactions at Sc sites in the semiconductorSc2O3: TDPAC andab initiostudy

Hyperfine interactions at 181 Hf ( Ta ) impurities implanted in Er 2 O 3 and Gd 2 O 3 : structural and electronic dependence of the EFG in bixbyite sesquioxides

Contact Info

Product

Resources

About