CN101962801A

CN101962801A - Method for rapidly growing Nb205 crystal

Info

Publication number: CN101962801A
Application number: CN 201010515975
Authority: CN
Inventors: 王越; 范修军; 徐宏; 蒋毅坚
Original assignee: Beijing University of Technology
Current assignee: Beijing University of Technology
Priority date: 2010-10-15
Filing date: 2010-10-15
Publication date: 2011-02-02
Anticipated expiration: 2030-10-15
Also published as: CN101962801B

Abstract

The invention discloses a method for rapidly growing Nb205 crystal, belonging to the field of Nb205 crystal growth. The method comprises the following steps: preparing Nb205 powder into biscuit rods; taking one biscuit rod as a seed crystal on a seed rod and hanging the other biscuit rod on a charge bar rod as a charge bar; causing the tail ends of the two charge bars to contact; forming a straight line with a halogen lamp at the contact part in the horizontal direction; causing the two charge bars to form a straight line in the vertical direction; in the air atmosphere, causing the halogen lamp of a single crystal furnace to reach a power output of 1600-1750W/h in 0.2-0.5h; heating to cause the contact part of the two charge bars to be melted so as to form a melting zone; retaining the power output, causing the seed rod and a raw material rod to rotate in the reverse direction at a velocity of 15-20rmp; and causing the raw material and the seed rod to move up and down at a velocity of 8-15mm/h to pass the melting zone to grow the crystal. The product of the invention has the characteristics of no impurities, simple instruments, low cost, fast growth speed and no need of special atmosphere.

Description

A kind of quick growth Nb 2O 5The crystalline method

Technical field

The invention belongs to Nb ₂O ₅Field of crystal growth is specifically related to a kind of Nb of quick growth centimetre magnitude ₂O ₅The crystalline method.

Background technology

Crystalline material plays crucial effect in scientific technological advance, be the important foundation stone of information age, also is the basic substance of development hi-tech.Crystalline material mainly contains: semiconductor single crystal material, laser crystal material, scintillator crystal materials, non-linear optical crystal material, piezoelectric crystal material, ferroelectric crystal material, magneto-optical crystal material, superconduction crystalline material.Main single crystal preparation technology mainly contains: melt growth, solution growth, vapor phase growth, solid state growth.Float-zone method belongs to a kind of method of melt growth, forms one section melting zone between the crystal of growth and polycrystalline rod, and melting zone stable is that the balance of abutment surface tension force and gravity is kept.Perhaps move, from top to bottom from bottom to top to finish crystallisation process in the melting zone.The heating source of float-zone method growing crystal has the RF induction heating, discharge, and electric arc, resistive heating, light focuses on.The growing method that light focuses on as heating source is called the optics float-zone method, and it is the light that light source is sent, and through focusing on as thermal source, delivers on the heated polycrystalline sample, treats after the polycrystalline fusing growing crystal.The early stage light source that uses is the light that sends with carbon arc, but work-ing life is extremely short, after use incandescent light as light source again, but the tungsten filament of incandescent light highly volatile at high temperature, the work-ing life of lamp is still very short.At present, the light source that infrared rays focuses on the process furnace use mostly is tungsten-iodine lamp or xenon lamp, and its Heating temperature reaches 2100 ℃ or 2800 ℃ respectively.So the float-zone method Heating temperature is not limited by the crucible fusing point, the high material of fusing point of therefore can growing, and the speed of growth is very fast, is widely used in high temperature refractory oxide and intermetallic compound growth.

The optics float-zone method has the crucible of need not as a kind of novel crystal growth method, pollutes and lacks, and advantages such as fast growth for some crystal that is difficult to growth (comprising the crystal that crystal pulling method can not be grown), easily pollutes, demonstrate very big superiority.Optics float-zone method crystal growth halogen be so that many high-melting-points can not heat with RF again, and needs various lifes to be achieved the growth of monocrystalline, for example TiO at the material of atmosphere ₂, Nd:YVO ₃, Yb ₃Fe ₅O ₁₂Deng the crystalline growth, however optics float-zone method growth Nb ₂O ₅The crystalline report seldom.

1976, people such as I.Shindo utilized optics float-zone method single crystal growing furnace, had grown out, and diameter is 6mm, and length is 80mm, along the Nb of (001) direction growth ₂O ₅Crystal (I.Shindo and H.Komatsu, Journal of Crystal Growth, 1,34 (1976): 152-153).Its growth velocity 2.0,4.0,6.0,8.0mm/h; Bubbling air speed is: 21/min; Rate of temperature fall is 50 ℃/h, 300 ℃/h.It is ellipsoid halogen lamp heating that this technology is used the single crystal growing furnace stove, and crystal mass is not high, and complex operation is repeatable poor.

2005, the Ph D dissertation of The Pennsylvania State University report, Manuspiya, Hathaikarn. utilized laser heated pedestal method (the laser-heated pedestal growth (LHPG) technique grow except Nb ₂O ₅Whisker (Manuspiya, Hathaikarn.Dissertation Abstracts International, B, 68-05 (2005): 3279).

Summary of the invention

The object of the present invention is to provide a kind of with the optics float-zone method,, simple to operate with the general industry powder under room temperature, normal pressure, air ambient as raw material, prepare the Nb of high-quality centimetre of magnitude fast ₂O ₅The crystalline processing method.

The present invention is achieved by the following scheme:

1) with Nb ₂O ₅The powder compacting in the rectangular rubber balloon of packing into places the rubber sphere that powder is housed etc. under the static pressure and to make the biscuit rod.

2) one of biscuit rod is fixed on the seed rod of single crystal growing furnace as seed crystal, one hangs on the charge bar bar as charge bar, regulates seed rod, charge bar bar position, makes the terminal contact of two charge bars, and contact position and halogen lamp are on the same sea line, and two charge bar in the vertical directions are in alignment.

3) in air atmosphere, the halogen lamp of single crystal growing furnace is exported at 0.2-0.5h reaches 1600-1750W/h in the time power, and heating is melted two charge bar contact positions, forms the melting zone; Keep the output of this power, seed rod and raw material bar be with the contrary direction rotation of 15-20rpm, raw material bar and seed rod respectively with the speed of 8-15mm/h to the upper and lower melting zone that moves through, carry out crystal growth according to the crystal growth pattern of routine.After crystal growth is finished, in the time halogen lamp output rating is reduced to 0 at 1-0.5h.

Compare the obvious advantage of technology of the present invention with existing technology

(1) Nb of this prepared ₂O ₅Crystalline size is bigger, does not have macroscopic defectss such as bubble, cloud layer, inclusion.Crystal morphology figure, x-ray diffractogram of powder, X ray twin crystal rocking curve, the transmission electron microscope diffraction pattern shows sample inclusion-free, mutually pure, is monocrystalline.

(2) this raw materials technology is the general industry powder, and is loose to ingredient requirement, do not need seed crystal, need not crucible, reduces preparation cost greatly.

(3) required instrument is simple, only needs crystal growing furnace, isostatic pressing machine power machine.

(4) use Nb that this technology is grown ₂O ₅Crystal operation is simple, only needs to regulate before crystal growth begins the position of seed crystal rod and fuel rod, regulates speed of rotation, the speed of growth in the process of growth, the halogen lamp output rating of single crystal growing furnace.

(5) do not need special atmosphere, pressure environment, only need to divide atmosphere can finish crystal growth, work simplification at normal pressure, air.

(6) this technology has fast growth (8-15mm/h) with respect to existing technology, and preparation cycle is short, and preparation efficiency significantly improves.

(7) this technology, charge bar do not need sintering, cut down the consumption of energy greatly.

Description of drawings

Fig. 1 is embodiment 1Nb ₂O ₅Crystal morphology figure;

Fig. 2 is embodiment 2 Nb of the present invention ₂O ₅Crystal powder and Nb ₂O ₅Original powder XRD figure spectrum;

Fig. 3 is embodiment 3Nb ₂O ₅Crystalline transmission electron microscope diffraction pattern;

Fig. 4 is embodiment 4Nb ₂O ₅Crystal is along the X ray twin crystal rocking curve of X-ray diffractogram (405) direction of (405) direction cleavage surface.

Embodiment

Below in conjunction with accompanying drawing the specific embodiment of the present invention is done and to be described in further detail.

Embodiment 1: the employed crystal growing furnace of present embodiment is the FZ-T-10000-VI-VPO-PC optics float-zone method crystal growing furnace that Japanese Crystal Systems Corporation produces.

(1) with Nb ₂O ₅The powder compacting in the rectangular rubber balloon of packing into places the rubber sphere that powder is housed etc. under the static pressure and to make the biscuit rod.

(2) be fixed on the crystal furnace seed rod as seed crystal making one of biscuit rod in (1), one hangs on the charge bar bar as charge bar.

(3) in air atmosphere, the halogen lamp of single crystal growing furnace is with the output of the power of 1600W/h, and seed crystal rod and fuel rod rotate with the contrary side of 15rpm respectively, fuel rod and seed crystal rod respectively with the speed of 8mm/h to the upper and lower melting zone that moves through, carry out crystal growth.

From Fig. 1: crystal morphology figure as can be seen, the Nb that makes ₂O ₅Crystal diameter is about 9-10mm, and length is 50-60mm, and is transparent, no scattering particles, no bubble, cloud layer.

Embodiment 2: the employed crystal growing furnace of present embodiment is the FZ-T-10000-VI-VPO-PC optics float-zone method crystal growing furnace that Japanese Crystal Systems Corporation produces.

(2) be fixed on the seed rod as seed crystal making one of biscuit rod in (1), one hangs on the charge bar bar as charge bar.

(3) in air atmosphere, the halogen lamp of single crystal growing furnace is with the output of the power of 1650W/h, and seed crystal rod and fuel rod rotate with the contrary side of 20rpm respectively, fuel rod and seed crystal rod respectively with the speed of 10mm/h to the upper and lower melting zone that moves through, carry out crystal growth.

From Fig. 2 Nb ₂O ₅Characteristic peak is sharp-pointed shown in the crystal powder x ray diffraction spectrogram, shows that prepared sample is a pure phase, and inclusion-free is the phase structure of homogeneous.

Embodiment 3: the employed crystal growing furnace of present embodiment is the FZ-T-10000-VI-VPO-PC optics float-zone method crystal growing furnace that Japanese Crystal Systems Corporation produces.

(3) in air atmosphere, the halogen lamp of single crystal growing furnace is with the output of the power of 1720W/h, and seed crystal rod and fuel rod rotate with the contrary side of 20rpm respectively, fuel rod and seed crystal rod respectively with the speed of 12mm/h to the upper and lower melting zone that moves through, carry out crystal growth.

From Fig. 3: Nb ₂O ₅Crystal transmission electron microscope diffraction pattern, as can be seen, diffraction spot is clear bright, is monocrystalline.

Embodiment 4: the employed crystal growing furnace of present embodiment is the FZ-T-10000-VI-VPO-PC optics float-zone method crystal growing furnace that Japanese Crystal Systems Corporation produces.

(3) in air atmosphere, the halogen lamp of single crystal growing furnace is with the output of the power of 1750W/h, and seed crystal rod and fuel rod rotate with the contrary side of 18rpm respectively, fuel rod and seed crystal rod respectively with the speed of 15mm/h to the upper and lower melting zone that moves through, carry out crystal growth.

From Fig. 4: the Nb2O5 crystal gets X-ray diffractogram along (405) direction cleavage surface, at the X ray twin crystal rocking curve figure of (405) direction as can be seen, the halfwidth FWHM of curve is 0.160 °, show that crystalline monocrystalline degree is very high, defectives such as no subgrain boundary can judge that the crystal of being grown is a monocrystalline.

Claims

1. quick growth Nb ₂O ₅The crystalline method is characterized in that, may further comprise the steps:

1) with Nb ₂O ₅The powder compacting in the rectangular rubber balloon of packing into places the rubber sphere that powder is housed etc. under the static pressure and to make the biscuit rod;

2) one of biscuit rod is fixed on the seed rod of single crystal growing furnace as seed crystal, one hangs on the charge bar bar as charge bar, regulate seed rod, charge bar bar position, make the terminal contact of two charge bars, and the contact position is in alignment with halogen lamp in the horizontal direction, and two charge bar in the vertical directions are in alignment;

3) in air atmosphere, the halogen lamp of single crystal growing furnace is exported at 0.2-0.5h reaches 1600-1750W/h in the time power, and heating is melted two charge bar contact positions, forms the melting zone; Keep the output of this power, seed rod and raw material bar be with the contrary direction rotation of 15-20rpm, raw material bar and seed rod respectively with the speed of 8-15mm/h to the upper and lower melting zone that moves through, carry out crystal growth according to the crystal growth pattern of routine.