Abstract:
The emphasis of this work has been in two areas of optical materials - the
crystal-chemical development of new optical frequency converters and the synthesis
and study of new hosts for Cr³⁺ luminescence and lasing.
A simple method has been developed to identify promising frequency-doubling
materials containing triangular oxoanions by estimation of nonlinear
susceptibilities. Implementation of this method and its results have generated
predictive capabilities in determining the relationships among crystal structure,
nonlinear properties, and threshold powers. The new noncentrosymmetric borate
SrLiB₉O₁₅ is discussed; its structure is built from a 3-dimensional condensation of
B₃0₇ units with channels alternately filled with Sr and Li atoms. From these
studies, a prescription for new pyroborate frequency converters has been
developed. The material CdC₁₂C₃H7NO₂, has been synthesized and structurally
characterized by single-ciystal X-ray diffraction.
Three new alkaline-earth beryllium borates, built from unique 2- and 3-
dimensional networks and frameworks, have been identified. The structure of
SrBe₂(B0₃)₂ consists of layers of composition [Be₂(BO₃)₂] interleaved by Sr atoms.
CaBeB₂O₅ is constructed from a Ca0₉ polyhedral network and a beryllium borate
network. In BaBe₂(B0₃)₂ the structure is composed of a beryllium borate
framework intermingled with a Ba-centered dodecahedral framework.
Several materials with potential as hosts for Cr³⁺ lasing have been analyzed.
The structural study of the laser host LiSrAIF6 revealed the distortions at the Al
site that contribute to the unique optical properties of the Cr³⁺ -doped crystals.
The family of solid state oxide A₆MM'(B0₃)₆ is one of the largest families of oxide
reported to date. Metal site preferences, disorder, solid solubility, and the
interrelationship between this structure and the layered structure type of
Ba₃Sc(B0₃)₃ are detailed. An optimal synthetic procedure has been developed for
these materials to provide pure, highly crystalline phases. Also, the structural and
optical features of (Cr³⁺:) Sr₃In(B0₃)₃ with A= Sr and M=M'= In have been
studied.
The material Sr₂LilnB₄O₁₀, was discovered while searching for a suitable
lithium borate flux for crystal growth of the compound Sr₃In(B0₃)₃.
