[go: up one dir, main page]

US3199961A - Growth of cadmium oxide single crystals - Google Patents

Growth of cadmium oxide single crystals Download PDF

Info

Publication number
US3199961A
US3199961A US197091A US19709162A US3199961A US 3199961 A US3199961 A US 3199961A US 197091 A US197091 A US 197091A US 19709162 A US19709162 A US 19709162A US 3199961 A US3199961 A US 3199961A
Authority
US
United States
Prior art keywords
cadmium oxide
single crystals
growth
carrier gas
vapor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US197091A
Inventor
Thomas C Macavoy
Jr James A Marley
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Corning Glass Works
Original Assignee
Corning Glass Works
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Corning Glass Works filed Critical Corning Glass Works
Priority to US197091A priority Critical patent/US3199961A/en
Application granted granted Critical
Publication of US3199961A publication Critical patent/US3199961A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01GCOMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G11/00Compounds of cadmium

Definitions

  • This invention relates to methods for growing crystals and more particularly to a method for growing large single crystals of high purity from polycrystalline materials.
  • FIG. 1 is a schematic representation, partly in section, of a crystal-growing furnace used in the process of the present invention.
  • FIG. 2 is a curve representing typical temperature 3,199,951 Patented Aug. 10, 1965 ice variations which may be maintained along the length of the furnace represented in FIG. 1.
  • Pure polycrystalline cadmium oxide 15 was placed, as illustrated in FIG. 1, in growth furnace 10, which comprises a hollow tube, or muffle, 11, around which are wound three independently controlled heating coils 12.
  • Muifle 11 is approximately 36" long and 1%" in inner diameter, although these dimensions may be varied.
  • the temperature gradient along the interval of approximately 20" which extends from cadmium oxide powder 15 through growth site 18 may be adjusted to conform to a typical curve, illustrated in FIG. 2, by independently regulating the power inputs to coils 12.
  • the carrier gas is introduced through inlet 16, and additional gases may be introduced through inlet 17 for purposes which will be hereinafter stated.
  • the gases introduced through inlets 16 and 17 travel over growth site 18, which is a removable tube closed at its end nearer the cadmium oxide powder, and emerge from outlet 19.
  • cadmium oxide powder 15 Approximately 50 grams of cadmium oxide powder 15 are placed as shown in the furnace illustrated in FIG. 1. The temperature within muffle 11 at this location is maintained high enough to permit vaporization of the cadmium oxide, or somewhere above 900 C., for example, approximately 1250 C., as indicated in FIG. 2. The temperature gradient along the remainder of muflle 11 is adjusted as indicated in FIG. 2.
  • the carrier gas transports the cadmium vapor and the oxygen which are formed by the vaporization of cadmium oxide along muflle 11 to the area of lower temperature found along growth site 13.
  • the lower temperatures cause progressively increasing supersatuation of the vapor, which results in condensation and crystallization of cadmium oxide along the growth site.
  • Mufile 11 is preferably made of platinum and growth site is is preferably made of magnesium oxide.
  • the qualityof the resultant cadmium oxide crystals is found to be far superior to that of crystals produced using other carrier gases.
  • the carrier gas is argon, which has a thermal conductivity approximately one-tenth that of helium, irregular crystal surfaces and numerous voids are found.
  • the only other carrier gas having a thermal conductivity of the same order of magnitude as helium is hydrogen. However, hydrogen cannot be used in growing oxide crystals since it would combine with the free oxygen.
  • Tube 17 is provided for the admission of additional oxygen between cadmium oxide powder 15 and growth site 18, in order to insure complete reoxidation of the cadmium vapor to form pure cadmium oxide crystals.
  • Cubic single crystals of cadmium oxide have been grown according to the present method up to 1 cm. on an edge.
  • helium carrier gases in producing by vapor deposition single crystals of the semi-conductor convert said cadmium oxide toa vapor, passing a carrier gas comprising helium over said quantity of cadmium oxide, carrying said vapor in said carrier gas to a growth site having a temperature within the range 800 C.-1260 0, whereby to deposit said vapor on said growth site in the form of at least one single crystal.
  • the method of producing single crystals of cadmium oxide which comprises the steps of heating a quantity of cadmium oxide to its sublimation temperature to convert said cadmium oxide to a vapor, passing over said quantity of cadmium oxide a carrier gas comprising helium, carrying said vapor in said carrier gas to a growth site having a temperature within the range 800 0-1260 C., and-injecting oxygen into said carrier gas in the vicinity of said growth site, whereby to deposit said vapor on said growth site in the form of at least one single crystal.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)

Description

Aug. 10, 1965 T. c. M AvoY ETAL 3,199,961
GROWTH OF CADMIUM OXIDE SINGLE CRYSTALS Filed May 23, 1962 POLYCRYSTALLINE C0 PLACEB lN Thus AREA R I000 Q o son-g1,
DIRECTION OF R CARRIER Gms 600 E I POSITION OF'G'ROWTH 400 ruse:
o a 4 6 8 IO la l4 16 I8 210 01s rA we: 41. o/va MUFFLE e l/vcwss INVENTORS Tao/was 6. M4c4vor Alva JAMES A. lVARL-gJk.
United States Patent 3,199,961 GROWTH OF CADMIUM ()XEDE SINGLE CRYSTALS Thomas C. MacAvoy and James A. Marley, .lr., Corning,
N .Y., assignors to Corning Glass Works, Corning, N.Y.,
a corporation of New York Filed May 23, 1962, Ser. No. 197,091 3 Claims. (or. 23-294) This application is a continuation-in-part of our copending application Serial No. 103,362, filed April 17, 1961, which application relates to the growth of large single crystals of stannic oxide.
This invention relates to methods for growing crystals and more particularly to a method for growing large single crystals of high purity from polycrystalline materials.
Experimentation subsequent to the filing of the cited application has shown the universality of an advantage observed in conjunction with the growth of stannic oxide crystals according to the method disclosed therein. In that application it was observed that unusually pure stannic oxide single crystals can be grown by a vapor deposition process wherein vapors produced by the sub limation of pure polycrystalline stannic oxide are transported by means of a helium carrier gas to a growth site, where they are deposited in the form of stannic oxide single crystals. Although it was not at that time known whether the advantages found in the use of helium as a carrier gas would be found in processes for growing single crystals of other materials by vapor deposition, it was believed that such might be the case, and it was hypothesized that the advantages might result from the high thermal conductivity of helium and its consequent ability to absorb and transport heat of crystallization away from the growing crystals.
It has since been determined that the use of helium as a carrier gas in the growth of single crystals by vapor deposition improves the quality of all single crystals so grown over that obtained with gases having lower thermal conductivities. It has been found that the improved quality is particularly apparent in the growth of single crystals of substances which themselves have low thermal conductivities, such as metallic oxides, where heat produced by crystallization at the surface of the growing crystal is particularly slow to dissipate through the crystals.
Accordingly, it is an object of this invention to provide an improved process for the vapor deposition of single crystals.
It is a further and more particular object of the invention to provide a method for the vapor deposition of large single crystals of cadmium oxide.
Although the invention will be hereinafter described as utilized in the production of single crystals of cadmium oxide, it will be understood that such description is given only by way of example and that the present invention, which resides in the use of helium as a carrier gas in the vapor deposition of single crystals, is applicable in the vapor deposition of single crystals of all materials. For example, but not by way of limitation, the process of the present invention will be found particularly advantageous in the vapor deposition of single crystals of the oxides of barium, zinc, magnesium, aluminum, indium, and beryllium.
The invention is illustrated in the accompanying drawing, in which:
FIG. 1 is a schematic representation, partly in section, of a crystal-growing furnace used in the process of the present invention, and
FIG. 2 is a curve representing typical temperature 3,199,951 Patented Aug. 10, 1965 ice variations which may be maintained along the length of the furnace represented in FIG. 1.
Pure polycrystalline cadmium oxide 15 was placed, as illustrated in FIG. 1, in growth furnace 10, which comprises a hollow tube, or muffle, 11, around which are wound three independently controlled heating coils 12. Muifle 11 is approximately 36" long and 1%" in inner diameter, although these dimensions may be varied. The temperature gradient along the interval of approximately 20" which extends from cadmium oxide powder 15 through growth site 18 may be adjusted to conform to a typical curve, illustrated in FIG. 2, by independently regulating the power inputs to coils 12. The carrier gas is introduced through inlet 16, and additional gases may be introduced through inlet 17 for purposes which will be hereinafter stated. The gases introduced through inlets 16 and 17 travel over growth site 18, which is a removable tube closed at its end nearer the cadmium oxide powder, and emerge from outlet 19.
The vaporization of cadmium oxide is believed to take place according to the equation:
2CdO= 2Cd+0 Accordingly, the process of the present invention is believed to operate by the generation of cadmium vapor and its subsequent reoxidation and deposition in the form of cadmium oxide single crystals.
Approximately 50 grams of cadmium oxide powder 15 are placed as shown in the furnace illustrated in FIG. 1. The temperature within muffle 11 at this location is maintained high enough to permit vaporization of the cadmium oxide, or somewhere above 900 C., for example, approximately 1250 C., as indicated in FIG. 2. The temperature gradient along the remainder of muflle 11 is adjusted as indicated in FIG. 2.
The carrier gas transports the cadmium vapor and the oxygen which are formed by the vaporization of cadmium oxide along muflle 11 to the area of lower temperature found along growth site 13. Here the lower temperatures cause progressively increasing supersatuation of the vapor, which results in condensation and crystallization of cadmium oxide along the growth site.
Mufile 11 is preferably made of platinum and growth site is is preferably made of magnesium oxide.
When helium is used as the carrier gas, the qualityof the resultant cadmium oxide crystals is found to be far superior to that of crystals produced using other carrier gases. When helium is utilized as the carrier gas, large single crystals are formed which are completely free of voids and imperfections, while, when the carrier gas is argon, which has a thermal conductivity approximately one-tenth that of helium, irregular crystal surfaces and numerous voids are found. The only other carrier gas having a thermal conductivity of the same order of magnitude as helium is hydrogen. However, hydrogen cannot be used in growing oxide crystals since it would combine with the free oxygen.
Tube 17 is provided for the admission of additional oxygen between cadmium oxide powder 15 and growth site 18, in order to insure complete reoxidation of the cadmium vapor to form pure cadmium oxide crystals.
Cubic single crystals of cadmium oxide have been grown according to the present method up to 1 cm. on an edge.
Although the advantages found in the use of helium as a carrier gas are particularly evident in the growth of metallic oxide crystals, improved crystals of other materials may be so produced. For example, it is advantageous to use helium carrier gases in producing by vapor deposition single crystals of the semi-conductor convert said cadmium oxide toa vapor, passing a carrier gas comprising helium over said quantity of cadmium oxide, carrying said vapor in said carrier gas to a growth site having a temperature within the range 800 C.-1260 0, whereby to deposit said vapor on said growth site in the form of at least one single crystal.
2. The method of producing single crystals of cadmium oxide which comprises the steps of heating a quantity of cadmium oxide to its sublimation temperature to convert said cadmium oxide to a vapor, passing over said quantity of cadmium oxide a carrier gas comprising helium, carrying said vapor in said carrier gas to a growth site having a temperature within the range 800 0-1260 C., and-injecting oxygen into said carrier gas in the vicinity of said growth site, whereby to deposit said vapor on said growth site in the form of at least one single crystal.
3. The method according to claim 1 in which said growth site comprises an area having a temperature varying between approximately1260 C. at a point near said quantity of cadmium oxide and approximately 800 C. at a point farther from saidquantity.
References Cited by the Examiner UNITED STATES PATENTS Re. 23,556 9/52 Mochel l17-106 1,161,885 11/15 Rigg 23-183 1,161,886 11/15 Rigg 23183 1,964,322 6/34 Hyde. 1,973,590 ll/34 Weaton et al. 2,474,645 10/ 39 V Barter 117106 OTHER REFERENCES Semiconductors by Hannay, pages 134 to 141, Feb. 27, 1959, Reinhold Pub.'Corp.
Lawson et al.: Preparation of Single Crystals.1958, pages 21 to 25, 89 to 92, and 204 to 209, Butterworth (London), QD 931 L3 195821.
Mellor: Comprehensive Treatise oflnorganic and Theoretical Chemistry. 4
NORMAN YUDKOFF, Primar Examiner. GEORGE D. MITCHELL, Examiner.

Claims (1)

1. THE METHOD OF PRODUCING SINGLE CYRSTALS OF CADMIUM OXIDE WHICH COMPRISES THE STEPS OF HEATING A QUANTITY OF CADMIUM OXIDE TO ITS SUBLIMATION TEMPERATURE TO CONVERT SAID CADMIUM OXIDE TO A VAPOR, PASSING A CARRIER GAS COMPRISING HELIUM OVER SAID QUANTITY OF CADMIUM OXIDE, CARRYING SAID VAPOR IN SAID CARRIER GAS TO A GROWTH SITE HAVING A TEMPERATURE WITHIN THE RANGE 800*C.-1260* C., WHEREBY TO DEPOSIT SAID VAPOR ON SAID GROWTH SITE IN THE FORM OF AT LEAST ONE SINGLE CRYSTAL.
US197091A 1962-05-23 1962-05-23 Growth of cadmium oxide single crystals Expired - Lifetime US3199961A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US197091A US3199961A (en) 1962-05-23 1962-05-23 Growth of cadmium oxide single crystals

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US197091A US3199961A (en) 1962-05-23 1962-05-23 Growth of cadmium oxide single crystals

Publications (1)

Publication Number Publication Date
US3199961A true US3199961A (en) 1965-08-10

Family

ID=22728015

Family Applications (1)

Application Number Title Priority Date Filing Date
US197091A Expired - Lifetime US3199961A (en) 1962-05-23 1962-05-23 Growth of cadmium oxide single crystals

Country Status (1)

Country Link
US (1) US3199961A (en)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1161885A (en) * 1913-09-04 1915-11-30 New Jersey Zinc Co Removing cadmium from zinc ore.
US1161886A (en) * 1915-07-27 1915-11-30 New Jersey Zinc Co Removing cadmium from zinc ore.
US1964322A (en) * 1930-11-07 1934-06-26 Corning Glass Works Electrically conducting coating on vitreous substances and method of producing it
US1973590A (en) * 1931-07-07 1934-09-11 St Joseph Lead Co Recovery of zinc, lead, tin, and cadmium values
US2474645A (en) * 1943-11-27 1949-06-28 Stanley M Baxter Process of producing stannic oxide
USRE23556E (en) * 1952-09-30 Electrically conducting coating on

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE23556E (en) * 1952-09-30 Electrically conducting coating on
US1161885A (en) * 1913-09-04 1915-11-30 New Jersey Zinc Co Removing cadmium from zinc ore.
US1161886A (en) * 1915-07-27 1915-11-30 New Jersey Zinc Co Removing cadmium from zinc ore.
US1964322A (en) * 1930-11-07 1934-06-26 Corning Glass Works Electrically conducting coating on vitreous substances and method of producing it
US1973590A (en) * 1931-07-07 1934-09-11 St Joseph Lead Co Recovery of zinc, lead, tin, and cadmium values
US2474645A (en) * 1943-11-27 1949-06-28 Stanley M Baxter Process of producing stannic oxide

Similar Documents

Publication Publication Date Title
US3721732A (en) Method of manufacturing filamentary bodies of circular cross-section consisting of silicon carbide single crystals and filamentary bodies obtained by said method
US4147572A (en) Method for epitaxial production of semiconductor silicon carbide utilizing a close-space sublimation deposition technique
JP3165685B2 (en) Sublimation growth of silicon carbide single crystal
US3634149A (en) Method of manufacturing aluminium nitride crystals for semiconductor devices
Slack et al. Growth of high purity AlN crystals
US3956032A (en) Process for fabricating SiC semiconductor devices
Ibuki On the crystal growth of cadmium sulphide
US3275415A (en) Apparatus for and preparation of silicon carbide single crystals
US3370927A (en) Method of angularly pulling continuous dendritic crystals
Clark et al. The preparation of large single crystals of cadmium sulphide
Cardetta et al. Growth and habit of GaSe crystals obtained from vapour by various methods
Reed et al. Growth of EuO, EuS, EuSe and EuTe single crystals
Harman et al. Preparation and Some Characteristics of Single‐Crystal Indium Phosphide
Wang et al. Single crystal growth of Zn3P2
Allred et al. The preparation and properties of aluminum antimonide
US3199961A (en) Growth of cadmium oxide single crystals
Chedzey et al. A study of the melt growth of single-crystal thiogallates
Vohl A technique for vapor phase growth of zinc selenide
US4202930A (en) Lanthanum indium gallium garnets
Powell Silicon carbide: Progress in crystal growth
Deguchi et al. Preparation Method of High Purity Aluminum Single Crystals with Low Dislocation Density
US3413098A (en) Process for varying the width of sheets of web material
White et al. The growth of highly perfect alumina platelets and other oxides by solvent vapour transport
JPH0645519B2 (en) Method for growing p-type SiC single crystal
Kuriyama Bridgman growth of lithium indium alloy single crystals