COMPOSITION ADJUSTMENT OF MELT FOR GROWING BISMUTH-SUBSTITUTED IRON GARNET FILM

• Main Authors: UMEZAWA HIROMITSU, YASUMA YASUHIRO
• Format: Patent
• Language: English
• Published: 04.02.1997
• Edition: 6
• Subjects: AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUSPOLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR; CHEMISTRY; CRYSTAL GROWTH; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; FREQUENCY-CHANGING; METALLURGY; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; REFINING BY ZONE-MELTING OF MATERIAL; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; SINGLE-CRYSTAL-GROWTH; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL ORUNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL

PROBLEM TO BE SOLVED: To realize a desired supersaturation temperature in a few repetition by growing a Bi-substituted iron garnet film under specific conditions from a melt of a certain composition on a specified substrate. SOLUTION: Using a melt of a certain composition, a Bi-substituted iron garnet film is subjected to liquid phase epitaxial growth on a specified substrate. The supersaturation temperature ΔT defined as the difference between saturated temperature Ts and the growth temperature To at which the respective lattice constants of the substrate and the garnet film coincide with each other in the above epitaxial growth process is determined. When the ΔT is out of a specified temperature range, at least one parameter of the two: R3 and RBi , defined as R3 =PbO/B2 O3 and RBi =Bi2 O3 /ζR2 O3 (R is Y or a rare earth element), is increased or decreased so that ΔT falls within the specified temperature range.