Diffusion assisted crystal hydrothermal and flux growth

Abstract

The purpose of diffusion assisted crystal hydrothermal growth is to facilitate a greatly increased crystal growth rate that would save time that is precious in such a material and manpower costly process. The assisted crystal growth itself requires the utilization of a piezoelectric shaker connected to the autoclave in which most industrial hydrothermal crystals are grown. The waveform can be modulated to induce transport of nutrient in a singular direction, customized to the topology of the apparatus. As it stands currently, the growth of most crystals that require autoclaves for their production can take anywhere from 3 months to up to 2 years, and accordingly carries many costs, particularly electricity and supervision of the autoclave(s), and other issues that may arise during the growth. While the product of this labor results in high-quality crystals, in reality, these are not at all what is needed outside of the laboratory environment. Using the assisted crystal hydrothermal growth process, average crystal growth can be cut in half, with the resulting crystals consequently being of a slightly lower quality, though still sufficient for most engineering purposes. Another advantage of using a piezoelectric shaker is that an additional sensor can be added to the autoclave to monitor the health of the autoclave using trending data obtained during the growth.

Claims

1) A piezoelectric shaker attached to the head of a high-pressure autoclave: a signal applied to such piezoelectric shaker, enough to produce mechanical movement inside the autoclave at least one sensor attached to the same autoclave to monitor health means for controlling the signal applied to the autoclave means to monitor the signal coming from the shaker

2) The apparatus as defined in claim 1, wherein the signal applied to the piezoelectric shaker is half-sine or with positive amplitude only, without applying the traditional full swing of the signal.

3) The apparatus as defined in claim 1, wherein the piezoelectric shaker accelerates crystal growth within the autoclave.

4) The apparatus as defined in claim 1, in which the resonance of the piezoelectric seeds matches the frequency applied to the piezoelectric shaker.

5) The apparatus as defined in claim 1, alternatively using a electrodynamic shaker.

6) The apparatus as defined in claim 1, alternatively using manual shaking via hammer.

7) The apparatus as defined in claim 1, in which the sensor is utilized to monitor the health and condition of the autoclave.

8) The apparatus as defined in claim 1, in which the sensor is utilized to monitor the growth of the crystals inside the autoclave.

9) The apparatus as defined in claim 1, in which such crystals as Gallium Orthophsophate, Berlinite, Gallium Arsenate, and other Quartz homeotypes are grown.

10) The method of accelerating crystal growth in a hydrothermal autoclave by mechanically improving the diffusion in the process of transporting nutrient to the seeds.

11) The method as defined in claim 10, in which different amplitudes and frequencies are applied to the shaker relating to the growth conditions.

12) The method as defined in claim 10, in which the trending data is taken from at least one sensor and related to the health of the autoclave.

13) The method as defined in claim 10, in which the trending data is taken from at least one sensor and related to the growth rate of the crystals.

14) The method as defined in claim 10, in which such crystals as Gallium Orthophsophate, Berlinite, Gallium Arsenate, and other Quartz homeotypes are grown.

15) The method as defined in claim 10, of saving resources such as energy, manpower, and time by fitting a piezoelectric shaker onto a hydrothermal autoclave.

16) The method as defined on claim 10, in which the flux method from the melt it is utilized to grow piezoelectric crystals.

17) The method as defined in claim 10, such that the quality of the crystals are optimized by the fewer number of impurities found in the grown crystals by the lack of deterioration of the autoclave which is monitored during the growth.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The foregoing and other objects, features, and advantages of my invention will be apparent from the following more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawings. The drawings are not necessarily made to scale, but instead are used to detail the nature and principle of the invention. The preferred embodiment(s) of the present invention is/are described in conjunction with the associated drawings in which like features are indicated with like reference numerals and in which

[0010] FIG. 1 is a frontal view of a high-pressure autoclave 1 for growing crystals like quartz in which typically the solubility increases with increased temperature, and thus the seeds 2 are kept at the top and the nutrient 3 is kept at the bottom, with a temperature gradient for circulation and separated by a baffle 4. The head 5 of the autoclave is exposed in the illustration.

[0011] FIG. 2A is a frontal view of a high-pressure autoclave 1 for growing crystals like quartz in which typically the solubility increases with increased temperature, and thus the seeds 2 are kept at the top and the nutrient 3 is kept at the bottom, with a temperature gradient for circulation and separated by a baffle 4 with the additional piezoelectric shaker 6 attached on the head 5 of the autoclave. Attached onto the side of the autoclave is an additional sensor 7 for monitoring the health of the autoclave.

[0012] FIG. 2B is a frontal view of a high-pressure autoclave 1 for growing crystals like gallium orthophosphate or Berlinite in which typically the solubility decreased (retrograde) with increased temperature, and thus the seeds 2 are kept at the bottom and the nutrient 3 is kept at the top, with a temperature gradient for circulation with the additional piezo-shaker 6 attached on the bottom of the autoclave. Attached onto the side of the autoclave is an additional sensor 7 for monitoring the health of the autoclave.

[0013] FIG. 3 is an example of two waveforms applied to the piezoelectric shaker 6, one to always produce movement in one direction, the half signal 9, and one that allows movement in both directions, the complete signal 8. The half signal waveform could be a ramp, half-sine, or pulse.

DESCRIPTION OF THE EMBODIMENTS

[0014] On one of the embodiments of my invention, a piezoelectric shaker 6 is located on the top of the autoclave 1 (FIG. 2A). The piezoelectric shaker 6 applies a waveform signal that translates to mechanical movement within the autoclave 1 during operation and increases the diffusion process of the nutrient 3 being transported to the crystal seeds 2, accordingly increasing crystal growth rate. This method for accelerating crystal growth as has been noted in previously, carries numerous advantages to conventional growth accelerants from being hypothetically safer to mechanical stirrers to being adaptable to different crystals via modifiable waveforms. In some cases, the piezoelectric shaker 6 will require isolation from the high-temperature autoclave 1, though this will depend on the growth conditions of the autoclave 1 and the shaker 6 used. Also note, that instead of piezoelectric shaker, other types of mechanical motion can be applied such as that by a electrodynamic shaker or a simple pendulum with a hammer. It should also be important to note that an additional sensor 7 can be fitted to the autoclave as well as the shaker to measure trending data and take other measurements from the autoclave to essentially measure the “health” of the autoclave and in some cases, measure the progress of growth in the autoclave. This sensor 7 can be an accelerometer, a strain gauge, or an ultrasonic sensor selected based upon the frequencies and amplitudes needed for growth. The monitoring of crystal growth via sensor 7 has never been done before in a scientific or industrial setting even though crystal growth is a perfect setting for such monitoring, due to the fact that during hydrothermal growth, there are no gases, solids, metals or liquids within the autoclave 1, only a mechanically ideal environment for transferring signals.

[0015] By utilizing, the apparatus as described above, a faster crystal growth rate can be achieved, to a level that the quality of the crystals is not compromised. As the industry stands today, the level of quality demanded results in growth periods for crystals that are entirely too long for proper industrial mass production and result in the atrocious wasting of valuable manpower, energy, and time. This embodiment can be used to grow just about any hydrothermal crystal from Quartz to Sapphire.

[0016] On another of the embodiments of my invention (FIG. 2B), the process is performed in almost exactly the same manner, except it is used on an inverted, retrograde autoclave 1 taking advantage of the fact that the piezoelectric shaker 6 can be placed on both the bottom and the top of the autoclave 1 with no loss of results. A characteristic of a piezoelectric shaker is that an electrical signal is converted into a mechanical signal, and by changing the polarity of the electrical signal, the resulting mechanical output can be changed as well. This embodiment can be used to grow crystals such as Gallium Orthophosphate, Berlinite, Gallium Arsenate, or any other Quartz homeotypes, that while currently may take up to a year to grow, can take as little as four months with my method.

[0017] Because many of the crystals grown by autoclave 1 are piezoelectric and the shaker 6 used is piezoelectric, the resulting phenomena could be that a combination of ideal conditions will result in the growing crystals aligning with the signal with synergy, similar to the phenomena of swinging pendulums aligning over time at a particular resonant frequency. The net effect is an improved crystal structure and rate of growth accelerated by my invention.

[0018] The same approach utilized onto an autoclave can be applied to the flux method, as the piezocicctric shaker might be attached to the crucible and produce the same effects of accelerating the diffusional transfer of nutrient to the seeds. The flux method can be used to grow also Gallium ortho Phosphate and other crystals grown by the melt, or in a flux.

[0019] The foregoing description of the preferred embodiment of the invention has been presented for the purposes of illustration and description. While this invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention in the following claims. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teachings. It is intended that the scope of the invention be limited not with this detailed description, but rather by the claims appended hereto.