Joseph W. Kolis

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The structural variations of several alkali metal rare earth fluoride single crystals are summarized. Two different stoichiometric formulations are considered, namely those of ARE2F7 and ARE3F10 (A = K, Rb, Cs; RE = Y, La-Lu), over a wide range of ionic radii of both the alkali and rare earth (RE) ions. Previously reported and several new single-crystal(More)
The use of high temperature hydrothermal reactions to prepare crystals having mineralogically-related structures is described. Complex naturally occurring minerals can have fascinating structures and exhibit important features like low dimensionality, noncentrosymmetry, or ion channels that can provide excellent guideposts for the designed synthesis of new(More)
Lanthanide borates, LnBO3 (Ln 1⁄4 La, Pr and Nd), were prepared via supercritical hydrothermal methods in sizes up to 3 0:5 0:5 mm and their crystallography and physical and optical properties studies. The materials are thermally stable up to at least 1000 C and their crystal structure, although previously thought to be centric orthorhombic, is shown to be(More)
A new mixed alkali/alkaline earth iron phosphate, NaBaFe4(HPO4)3.H2O, has been synthesized hydrothermally and structurally characterized by single-crystal X-ray diffraction, magnetic susceptibility, infrared spectroscopy, and thermogravimetric analysis. The title compound crystallizes in the monoclinic space group P2(1)/c (No. 14) with a = 9.287(2) A, b =(More)
The reaction of barium borosilicate glasses in hydrothermal fluids with NaOH mineralizer at ca. 600-650 °C in the presence of various sources of Eu(3+) ions leads to a new series of noncentrosymmetric single crystals characterized by single-crystal X-ray diffraction. Under three slightly different reaction modifications, three new Eu(3+)-containing(More)
Two novel, noncentrosymmetric borate fluorides, Sr(3)B(6)O(11)F(2) and Ba(3)B(6)O(11)F(2), have been synthesized hydrothermally and their structures determined. The compounds are isostructural, crystallizing in space group P2(1), having lattice parameters of a = 6.4093 (13) Å, b = 8.2898 (17) Å, c = 9.3656 (19) Å, and β = 101.51 (3)° for Sr(3)B(6)O(11)F(2)(More)
We have developed an angle-resolved photoemission spectrometer with tunable vacuum ultraviolet laser as a photon source. The photon source is based on the fourth harmonic generation of a near IR beam from a Ti:sapphire laser pumped by a CW green laser and tunable between 5.3 eV and 7 eV. The most important part of the set-up is a compact, vacuum enclosed(More)
A new structural member of the broad class of A3RESi6O15 compounds has been discovered for the formula Cs3RESi6O15, where RE = Dy-Lu,Y,In. The structure is unusual in that it contains octahedrally coordinated rare earth ions whose relative orientation dictates the structure as they rotate about the c-axis supported by the cyclic Si6O15 framework. The repeat(More)
A new series of transition metal vanadates, namely, Ba2M(VO4)2(OH) (M = V(3+), Mn(3+), and Fe(3+)), was synthesized as large single crystals hydrothermally in 5 M NaOH solution at 580 °C and 1 kbar. This new series of compounds is structurally reminiscent of the brackebuschite mineral type. The structure of Ba2V(VO4)2(OH) is monoclinic in space group P21/m,(More)