Lanthanum titanates single-crystal and upgrowth technology thereof

A technology of lanthanum titanate and crystal growth, applied in the direction of single crystal growth, single crystal growth, crystal growth, etc., can solve problems such as difficulty in ensuring composition and structure uniformity, easy introduction of impurities, etc.

Active Publication Date: 2007-10-31
苏州晶生新材料有限公司
View PDF0 Cites 8 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although polycrystalline ceramic LTO is easy to prepare, it is easy to introduce impurities during the preparation process, forming a large number of pores, and it is difficult to ensure the uniformity of composition and structure, and these factors play a decisive role in the preparation of high-quality LTO films.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Lanthanum titanates single-crystal and upgrowth technology thereof
  • Lanthanum titanates single-crystal and upgrowth technology thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0048] TiO with a purity of 99.9 wt% 2 and 99.999wt% La 2 o 3 Press La 2 Ti 2 o 7 The chemical composition ingredients are mixed, and the mixed powder is ground and mixed evenly on a mortar or grinder, at 2t / cm 2 Pressed into a pellet under isostatic pressure; then placed in a cylindrical crucible together with a seed crystal of the selected orientation . The crucible is placed in the descending furnace and adjusted to a certain height. After the whole system is sealed, it is energized and heated up. The mechanical pump and the diffusion pump are started successively, and the vacuum is pumped to 10 -3 Pa, when the furnace temperature reaches 1500°C, fill it with 99.99% by volume of argon, continue to heat up to 1850°C, melt the raw material and adjust the position of the furnace to melt the top of the seed crystal, perform inoculation and growth, and the temperature gradient of the growth interface is maintained at 30 ℃ / cm, lower the crucible at a rate of 3 mm / h, and gro...

Embodiment 2

[0051] TiO with a purity of 99.99wt% 2 and 99.999wt% La 2 o 3 Press La 2 Ti 2 o 7 The chemical composition ingredients are mixed, and the mixed powder is ground and mixed evenly on a mortar or grinder, at 3t / cm 2 Pressed into cubes under the isostatic pressure; and then placed into a rectangular cylindrical crucible together with a rectangular cylindrical seed crystal in the direction. The crucible is placed in the descending furnace and adjusted to a certain height. After the whole system is sealed, the temperature is energized and the vacuum is pumped to 10 -4 Pa, when the furnace temperature reaches 1600°C, fill it with 99.99% by volume argon, continue to raise the temperature, control the furnace temperature at 1900°C, melt the raw material and inoculate and grow, the temperature gradient of the growth interface is about 60°C / cm, and the temperature gradient is 8.8mm / The crucible is lowered at a rate of h, and a rectangular columnar LTO complete crystal is grown. ...

Embodiment 3

[0053] TiO with a purity of 99.9 wt% 2 and 99.999wt% La 2 o 3 Press La 2 Ti 2 o 7 The chemical composition ingredients are mixed, the mixed powder is ground and mixed evenly on a mortar or grinder, and pressed into a round block; respectively put into three crucibles with a diameter of 70mm, and then placed in a high-temperature drop furnace with three crucible positions, adjust After reaching a certain height, the whole system is sealed and energized to heat up, and then vacuumed to 10 -2 Pa, when the furnace temperature reaches 1700°C, fill it with 99.99% by volume argon, continue to raise the temperature, and control the furnace temperature at 1950°C. Adjust the furnace entry positions of the three crucibles so that the seed crystals in each crucible can be inoculated well. The temperature gradient of the growth interface is about 70°C / cm, and the crucible descending rate is 1.0mm / h. Three cylinders can be obtained at the same time. like LTO crystals. After the cryst...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention discloses a lanthanum titanate crystal with chemical composition as La2Ti2O7 and growing technology, which comprises the following steps: (1) adopting TiO2 and La2O3 as initial raw material; choosing the usage ration in pursuance of chemical composition of La2Ti2O7; mixing evenly; briquetting; (2) transferring copple with briquette raw material of the step (1) into vacuum reduced furnace; heating the whole system; evacuating to 10-2-10-4Pa; charging into inert protective gas when temperature at 1500-1700 deg. c; heating to setting temperature continually; setting the setting temperature at 1850-1950 deg. c; (3) adjusting the position of copple in furnace tank; melting the raw material and seed crystal top; realizing seeding growth; controlling solid-liquid interface thermal gradient of crystal growth at 20-80 deg. c/cm; controlling dropped ratio at 0. 2-10mm/h; (4) finishing the crystal growth; decreasing the temperature to room temperature with 30-120 deg. c/h speed; annealing for crystal. This product possesses good crystallization property, big dielectric constant and high refracting power.

Description

technical field [0001] The present invention relates to a single crystal of lanthanum titanate and a growth method for preparing a single crystal of lanthanum titanate, more specifically to a single crystal of lanthanum titanate with high dielectric and high refractive index, and the growth technology of the single crystal by the crucible drop method . The invention belongs to the field of single crystal growth. Background technique [0002] Lanthanum titanate crystal La 2 Ti 2 o 7 (hereinafter sometimes referred to as LTO) belongs to the monoclinic system, perovskite-like structure, and the space group at room temperature is P2 1 . LTO crystals have good ferroelectric, photocatalytic, and electro-optical properties, and have broad application prospects in the fields of light and electricity. It has a very high Curie temperature (1500°C) and a large coercive field (45kV / cm), and can be used in high-temperature electro-optic devices and information storage, such as high...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C30B29/32C30B15/08
Inventor 吴宪君李新华徐家跃张道标顾宝林
Owner 苏州晶生新材料有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap