Growth and characterization of ferroelectric single crystal fibers produced by the laser-heated pedestal growth technique

Single crystal fibers were grown using the laser-heated pedestal growth (LHPG) technique. The laser-heated pedestal growth (LHPG) technique is a containerless crystal growth method, similar to the float zone method, that employs a carbon dioxide laser as the power source. The two general aims of the thesis were to assemble an LHPG station at the Materials Research Laboratory and to grow ferroelectric single crystal fibers.; Focus was directed towards the growth of two families of materials in order to exploit three important features of the LHPG technique: the crucibleless nature and hence the capability to grow refractory materials, the rapid growth rates possible with this technique, and the ability to grow both incongruently and congruently melting compositions. The layered perovskite and strontium barium niobate solid solution families were investigated in this work.; All the members of the layered perovskite family A{dollar}sb2{dollar}B{dollar}sb2{dollar}O{dollar}sb7{dollar}, are congruently melting and most are characterized by very high melting points (m.p. {dollar}>{dollar} 1800{dollar}spcirc{dollar}C). Single crystal La{dollar}sb2{dollar}Ti{dollar}sb2{dollar}O{dollar}sb7{dollar}, Nd{dollar}sb2{dollar}Ti{dollar}sb2{dollar}O{dollar}sb7{dollar} and Ca{dollar}sb2{dollar}Nb{dollar}sb2{dollar}O{dollar}sb7{dollar} fibers were grown with an average diameter of 500{dollar}mu{dollar}m. Their crystal quality and piezoelectric and dielectric properties were measured and compared to crystals grown by other methods.; Single crystal fibers of the strontium barium niobate solid-solution family were grown, with compositions extending across the solid solution range. The relationship between growth rate, molten zone shape and stability, and the liquid-solid interface on the crystal quality was investigated. The effect of the growth conditions on the composition, electrical, and optical properties were investigated and compared to crystals grown by the Czochralski technique.