Effects of substitution chemistry in the KTiOPO[sub 4] structure field

Journal Article · · Chemistry of Materials; (United States)

OSTI ID:6493401

Phillips, M L.F. ^[1]; Harrison, W T.A.; Stucky, G D ^[2]; McCarron, III, E M; Calabrese, J C; Gier, T E ^[3]

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1. Sandia National Lab., Albuquerque, NM (United States)
2. Univ. of California, Santa Barbara, CA (United States)
3. E.I. du Pont de Nemours, Wilmington, DE (United States)

Potassium titanyl phosphate (KTiOPO[sub 4], or KTP) is an important nonlinear optical medium whose structure permits a moderate degree of cation mobility. This feature is exploited in the synthesis of Na[sub 0.95]K[sub 0.05]TiOPO[sub 4] (NaTP), Ag[sub 0.85]K[sub 0.15]TiOPO[sub 4] (AgTP), and Na[sub 0.87]K[sub 0.13]TiOAsO[sub 4] (NaTA) from single crystals of KTP and KTiOAsO[sub 4] (KTA) through ion exchange at low temperatures, as these compositions do not crystallize in the KTP structure type when prepared from their constituent oxides at high temperatures. All three compounds are orthorhombic, space group Pna2[sub 1]. Crystals of [alpha]-NaTiOPO[sub 4], the high-temperature polymorph of NaTP, were prepared hydrothermally. This phase crystallizes in the titanite (CaTiOSiO[sub 4]) structure and is monoclinic, space group P2[sub 1]/c, from those in KTP or KTA. Second harmonic generation intensities measured at 532 nm show that optical nonlinearity in NaTP and AgTP is significantly attenuated from that in KTP and NaTA. These results are accounted for by (1) differences in interactions between K, Na, Ag, and the titanyl oxygen atoms, which influence the mixing of a delocalized excited state into the ground-state bonding and nonbonding framework orbitals, and (2) a decrease in bandgap due to the increased basicity of the oxygen atoms in the arsenate derivatives. 41 refs., 8 figs., 8 tabs.

• DOE Contract Number: AC04-76DP00789
• OSTI ID: 6493401
• Journal Information: Chemistry of Materials; (United States), Vol. 4:1; ISSN 0897-4756
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ARSENATES
OPTICAL PROPERTIES
OXIDES
PHOSPHATES
POTASSIUM COMPOUNDS
SILVER COMPOUNDS
SODIUM COMPOUNDS
TITANIUM COMPOUNDS
CHEMICAL PREPARATION
HYDROTHERMAL SYNTHESIS
ION EXCHANGE
MONOCLINIC LATTICES
NONLINEAR OPTICS
ORTHORHOMBIC LATTICES
ALKALI METAL COMPOUNDS
ARSENIC COMPOUNDS
CHALCOGENIDES
CRYSTAL LATTICES
CRYSTAL STRUCTURE
OPTICS
OXYGEN COMPOUNDS
PHOSPHORUS COMPOUNDS
PHYSICAL PROPERTIES
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
360606* - Other Materials- Physical Properties- (1992-)
360602 - Other Materials- Structure & Phase Studies