Hydrothermal Preparation, Structures, and NLO Properties of the Rare Earth Molybdenyl Iodates, RE(MoO2)(IO3)4(OH) [RE = Nd, Sm, Eu]

Shehee, T. C.; Sykora, Richard E.; Ok, Kang Min; Halasyamani, P. Shiv; Albrecht‐Schmitt, Thomas E.

doi:10.1021/ic025992j

Cited by 111 publications

(81 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[27] Cs 2 I 4 O 11 has an SHG efficiency of approximately 300 SiO 2 . This efficiency is comparable to other NCS iodates, including HIO 3 (300 SiO 2 ), [26] LiIO 3 (300 SiO 2 ), [26] NdMoO 2 (IO 3 ) 4 (OH) (350 SiO 2 ), [28] and AMoO 3 (IO 3 ) (A = Rb or Cs, 400 SiO 2 ). [29] By sieving the polycrystalline powder into various particle sizes (20-150 mm) and measuring the SHG as a function of particle size, we were able to determine that Cs 2 I 4 O 11 is non-phasematchable (Type 1).…”

Section: +supporting

confidence: 62%

The Lone‐Pair Cation I⁵⁺ in a Hexagonal Tungsten Oxide‐Like Framework: Synthesis, Structure, and Second‐Harmonic Generating Properties of Cs₂I₄O₁₁

2004

Self Cite

View full text Add to dashboard Cite

Noncentrosymmetric (NCS) oxides exhibit a variety of technologically important properties including ferroelectricity, piezoelectricity, pyroelectricity, and second-order nonlinear optical behavior. [1][2][3] The rational design of new NCS materials, however, remains a challenge, although a number of strategies have been suggested. [4][5][6][7][8][9] We have focused on synthesizing materials containing cations with lone pairs (e.g., Sb 3+ , Se 4+ , Te 4+, etc.) in order to increase the incidence of NCS in any new compound. [10,11] A structural topology that is often observed in NCS is the hexagonal tungsten oxide (HTO) framework. This structure has been reported for a variety of cations, including V 5+ , Mo 6+ , W 6+, and Sb 5+. [12][13][14][15][16][17][18] The framework consists of corner-sharing MO6 = 2 octahedra that are linked to form an array of three-and six-membered rings. [20-24] The IO 5 and IO 3 polyhedra share corners to form the layered structure. In connectivity terms, the layer can be described as a [3(2À anion, with charge balance attained by two Cs + cations. One of the most novel aspects of the structure is the twodimensional IO 5 layer (Figure 1). The HTO-like layer consists of six-membered rings containing corner-sharing IO 5 polyhedra in alternating orientation as one proceeds around the ring. Cs 2 I 4 O 11 is the first example of a lone-pair cation in a HTO-like topology. In the rings themselves, three lone pairs point inward and three outward. Thus, the lone pairs and oxide anions alternate around the ring. The lone pairs have two important structural consequences. First, the local dipole moment on each IO 5 polyhedron is in the direction of the lone pair. If we sum all of the dipole moments with respect to the IO 5 group, the resultant moment is zero. In other words, there is complete cancellation of the dipole moments with respect to the IO 5 polyhedra, that is, the IO 5 layer is pseudocentrosymmetric. This type of pseudocentrosymmetric layer was observed previously in Rb 2 TeW 3 O 12 and Cs 2 TeW 3 O 12 .[17] The cancellation is relevant to the SHG efficiency. Second, the Cs + cations are not coplanar with the IO 5 ring, attributable to the lone pairs. As shown in Figure 2, the Cs + cations sit above and below the rings. The environments of the Cs + cations influence any possible ion-exchange capabilities of the material.[25] The IO 5 layer is capped on one side by an asymmetric three-coordinate I 5+ cation, that is, an IO 3 group (see Figure 3). Alignment of the IO 3 polyhedra in the [001] direction results in an NCS and polar structure. The lone pairs associated with the IO 3 polyhedra also point along the [001]

show abstract

Section: +supporting

confidence: 62%

The Lone‐Pair Cation I⁵⁺ in a Hexagonal Tungsten Oxide‐Like Framework: Synthesis, Structure, and Second‐Harmonic Generating Properties of Cs₂I₄O₁₁

2004

Self Cite

View full text Add to dashboard Cite

show abstract

“…For the monoclinic compound 2,t he calculated rotationa ngle between the crystallographic axes and the dielectric principle axes is 25.928.C onsidering the restriction of Kleinman's symmetry,c ompounds 1 (Cmc2 1 )a nd 2 (C2) have three (d 15 To investigate the origin of such strong SHG effects, we have performed the spectral decomposition of d 15 for compound 1 and of d 23 for compound 2,w hich are plottedi nt he bottommost panels of Figure 7. For compound 1,t he most contributing regions are just the upper part of VB (À1.76 0eV) and the bottommost CB (< 3.44 eV) corresponding to the O-2p non-bondings tates mixingw ith small amount of Aud xy states and the unoccupied antibonding states formed by Au-d x 2 Ày 2 and bridged O-2p, respectively.C ompared to compound 1,c ompound 2 has ar elativelyb roaderc ontributed region in the CB, which extends to 5.35 eV.I ts uggests that except the AuÀOa ntibonding states, the I-5p and other O-2p states also give some contributions to the SHG coefficient d 23 in the CB of compound 2.…”

Section: Theoretical Studiesmentioning

confidence: 99%

“…Another effective route for designing new NLO metal iodates is the incorporation of as econd cation into the ternary metal iodates, which affords abundant new structures. [15][16][17][18][19][20][21] Mostly,t ransition-metal ions with d 0 electronic configurations (i.e.,T i 4 + ,N b 5 + ,V 5 + ,M o 6 + ,e tc.) are introducedi nto iodates becauset hey usually form distorted MO 6 (M represent the d 0 transitionm etal)o ctahedra, which are also polar and SHG active.…”

Section: Introductionmentioning

confidence: 99%

K₂Au(IO₃)₅ and β‐KAu(IO₃)₄: Polar Materials with Strong SHG Responses Originating from Synergistic Effect of AuO₄ and IO₃ Units

et al. 2016

Chemistry A European J

View full text Add to dashboard Cite

Two new polar potassium gold iodates, namely, K2 Au(IO3)5 (Cmc21) and β-KAu(IO3)4 (C2), have been synthesized and structurally characterized. Both compounds feature zero-dimensional polar [Au(IO3)4](-) units composed of an AuO4 square-planar unit coordinated by four IO3(-) ions in a monodentate fashion. In β-KAu(IO3)4, isolated [Au(IO3)4](-) ions are separated by K(+) ions, whereas in K2 Au(IO3)5, isolated [Au(IO3)4](-) ions and non-coordinated IO3(-) units are separated by K(+) ions. Both compounds are thermally stable up to 400 °C and exhibit high transmittance in the NIR region (λ=800-2500 nm) with measured optical band gaps of 2.65 eV for K2 Au(IO3 )5 and 2.75 eV for β-KAu(IO3)4. Powder second-harmonic generation measurements by using λ=2.05 μm laser radiation indicate that K2 Au(IO3)5 and β-KAu(IO3)4 are both phase-matchable materials with strong SHG responses of approximately 1.0 and 1.3 times that of KTiOPO4, respectively. Theoretical calculations based on DFT methods confirm that such strong SHG responses originate from a synergistic effect of the AuO4 and IO3 units.

show abstract

“…The lone-pair cation coordination environment may be considered as pre-distorted, [38] as these cations are almost always found in local NCS environments. Halasyamani et al, [38][39][40][41][42][43][44][45][46][47][48][49][50] Norquist et al, [51][52][53] and others [54][55][56][57][58][59][60][61][62][63] have used SOJT-distorted cations in the design and synthesis of new NCS materials.…”

Section: Electronic Distortionsmentioning

confidence: 99%

Hydrothermal Preparation, Structures, and NLO Properties of the Rare Earth Molybdenyl Iodates, RE(MoO₂)(IO₃)₄(OH) [RE = Nd, Sm, Eu]

Cited by 111 publications

References 57 publications

The Lone‐Pair Cation I⁵⁺ in a Hexagonal Tungsten Oxide‐Like Framework: Synthesis, Structure, and Second‐Harmonic Generating Properties of Cs₂I₄O₁₁

The Lone‐Pair Cation I⁵⁺ in a Hexagonal Tungsten Oxide‐Like Framework: Synthesis, Structure, and Second‐Harmonic Generating Properties of Cs₂I₄O₁₁

K₂Au(IO₃)₅ and β‐KAu(IO₃)₄: Polar Materials with Strong SHG Responses Originating from Synergistic Effect of AuO₄ and IO₃ Units

Noncentrosymmetric Inorganic Oxide Materials: Synthetic Strategies and Characterisation Techniques

Contact Info

Product

Resources

About

Hydrothermal Preparation, Structures, and NLO Properties of the Rare Earth Molybdenyl Iodates, RE(MoO2)(IO3)4(OH) [RE = Nd, Sm, Eu]

Cited by 111 publications

References 57 publications

The Lone‐Pair Cation I5+ in a Hexagonal Tungsten Oxide‐Like Framework: Synthesis, Structure, and Second‐Harmonic Generating Properties of Cs2I4O11

The Lone‐Pair Cation I5+ in a Hexagonal Tungsten Oxide‐Like Framework: Synthesis, Structure, and Second‐Harmonic Generating Properties of Cs2I4O11

K2Au(IO3)5 and β‐KAu(IO3)4: Polar Materials with Strong SHG Responses Originating from Synergistic Effect of AuO4 and IO3 Units

Noncentrosymmetric Inorganic Oxide Materials: Synthetic Strategies and Characterisation Techniques

Contact Info

Product

Resources

About

Hydrothermal Preparation, Structures, and NLO Properties of the Rare Earth Molybdenyl Iodates, RE(MoO₂)(IO₃)₄(OH) [RE = Nd, Sm, Eu]

The Lone‐Pair Cation I⁵⁺ in a Hexagonal Tungsten Oxide‐Like Framework: Synthesis, Structure, and Second‐Harmonic Generating Properties of Cs₂I₄O₁₁

The Lone‐Pair Cation I⁵⁺ in a Hexagonal Tungsten Oxide‐Like Framework: Synthesis, Structure, and Second‐Harmonic Generating Properties of Cs₂I₄O₁₁

K₂Au(IO₃)₅ and β‐KAu(IO₃)₄: Polar Materials with Strong SHG Responses Originating from Synergistic Effect of AuO₄ and IO₃ Units