JPS58130197A - Manufacture of artificial alexandrite cat's-eye - Google Patents

Abstract

PURPOSE:To efficiently manufacture the titled cat's-eye of high quality by filling a powdered starting material having a compositional ratio close the that of alexandrite cat's-eye into a rubber tube, molding it into the shape of a rod, sintering the molded body, and synthesizing a crystal by a floating zone (FZ) method using a specified seed crystal. CONSTITUTION:A powdered starting material consisting of beryllium oxide, aluminum oxide, iron oxide, chromium oxide and titanium oxide in a compositional ratio close to that of alexandrite cat's-eye (product) is filled into a rubber tube, molded into the shape of a rod by a rubber pressing method, and sintered at 1,200-1,700 deg.C to form a starting material rod. A crystal is synthesized from the rod by a known floating zone method using an alexandrite single crystal, a product crystal or a sintered starting material rod of a product as a seed crystal. By annealing the synthesized crystal at 1,200-1,700 deg.C, titanium oxide crystals are deposited to obtain the desired product. The growing speed during the synthesis is regulated to 0.5-5.0mm./hr. By this method expensive cat's-eye which is slightly produced in nature can be provided inexpensively to the market.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention *＠d produces artificial alexandrite cat's eye crystals, which have been difficult to achieve in the past, by using the aluminum oxide-titanium oxide l&l# body as a raw material for the synthesis of artificial alexandrite cat's eye crystals. The present invention relates to a method for synthesizing large, high-quality crystals and gold with high efficiency in synthesis using the crystalline tFz method.

Conventionally, alexandrite has been easily synthesized by the FZ method and the flux method. Also, is alexandrite cat's eye a nail-shaped crystal of 61' titanium in alexandrite? This is because it is precipitated in this direction, and exhibits the cat's eye effect.

For this reason, alexandrite 2) Since it is synthesized by the IFz method, titanium oxide is added to the raw material of alexandrite. I did this. Shigashi titanium oxide 1
Since it did not dissolve into alexandrite, it became a polycrystalline rod and could not be synthesized. To solve this problem, the present invention uses a fermented aluminum-titanium oxide solid solution as a raw material. At this time, as shown in FIG. 1, if the molar ratio of aluminum oxide and titanium oxide is 11:1, a complete solid solution will occur, but if the composition ratio is other than this, the aluminum oxide-titanium boroside solid will not precipitate alone. Aji who is uninventive and has no membership fee! The amount of titanium oxide in the solid body is within 6 WTo. This is a5! The aluminum oxide-titanium oxide solid column shown in FIG. 1 does not precipitate. Therefore, the desired aluminum oxide-titanium oxide solid solution can be obtained by rapidly cooling and solidifying the aluminum monide-titanium oxide melt having the above composition. Using this tube, the composition ratio of aluminum oxide and beryllium oxide in the solid solution is adjusted to approximately the composition of chrysoberyl. That is, it is a condensed binary compound of aluminum oxide-titanium fluoride solid and beryllium oxide.

Iron oxide and chromium oxide powder, which are essential for color change, are added to this to create the raw material for alexandrite cat's eye.

The synthesis method is the known yz method. That is, the above raw material $4 is packed into a rubber tube and shaped into a cylindrical rod (M) using a rubber press method. (The diameter and length of this rod are changed depending on the necessity.)
It is sintered into raw material rods.

At this time, if the temperature is below 1200℃, the sintering will be insufficient and the temperature will reach 17.
Since there is a possibility that the raw material rod may melt in the bath at 00°C tflijLb, sintering is performed between 1200°C and 1700°C. The seed crystal shall be one of alexandrite single crystal, hyalexandrite sintered raw material rod, alexandrite cat's eye crystal, and alexandrite cat's eye sintered raw material rod.

Next, as a synthesis condition, the growth rate is α5 W/hr −S
It is assumed to be O■/hr. That is, if the growth rate is less than α5 m/hr, the growth rate f is too slow, which is disadvantageous for obtaining a high-quality large-sized single crystal.

Furthermore, if the synthesis tube is run at a speed of 5.0 m/hr or more, the desired high-quality crystals cannot be obtained. When the amount of titanium oxide increases, it is necessary to increase the growth rate *'.

This is because when the amount of titanium oxide increases, even if an attempt is made to dissolve titanium oxide into a solid solution by forming a solid binary solid solution of solid aluminum-diluted titanium solid solution and beryllium oxide, the titanium oxide cannot be dissolved in solid solution. In order to prevent this, the growth rate is increased by 1-1 and the titanium is forcibly dissolved in alexandrite.

Next, as a growth force direction, cane is grown in the direction of recognition, n, 6
゜That is, nail-shaped crystals of titanium oxide always precipitate parallel to the direction of growth force. Good direction H(100)(010) to 41
(001-). This is to make it easier to cut the alexandrite in the direction with the best discoloration. Other growth conditions follow the known PZ method.

Since the synthesized crystalline Fi titanium oxide is in a 1iIil bath, annealing is performed at 120 (10 to 1,700°C) to precipitate it. At an il lower than 1,200°C, titanium oxide crystals do not precipitate. If it is higher than t7001c, The crystals melt in the bath, the appropriate temperature is 1400-17, which is close to the melting point.
It is 00'C. The direction of precipitation of titanium oxide crystals is the same as the direction of growth force.

Unexploded #4 Alexandrite cat's eye is a gem S material that occurs naturally in very small quantities and is very expensive.
This makes it possible to provide products widely to the general public at low prices.

The effects of the present invention are even more powerful! An example is given below to demonstrate this.

<Real size f11> (1) 94 tons of raw material aluminum oxide and 4 fl of titanium oxide are mixed together in an all-iridium crucible, melted at 2050°C in an argon or nitrogen atmosphere, and rapidly cooled and solidified. . Grind 50f of this. This is followed by saponified beryllium t-12, Of.

Add 8t of iron oxide t-α and 12ft of chromium alumide and mix well.

(2) Preparation of raw material rod The raw material powder of (1) is packed into a rubber tube with a diameter of 15 square meters and a length of 1010 Os is made into a rod with air removed. This is formed into a υ cylindrical rod using the rubber press method. This was sintered at 1700° C. for 4 hours to obtain a raw material rod with a diameter of 10 cm and a length of 80 cm.

(Produced in 31 Crystal Synthesis + 21 and used as a raw material rod and an alexandrite cat's eye crystal as a seed crystal, it was carried out under Queen's growth conditions by the IF7 method.

Growth direction: (OOl) Shaft (b) rotation (both upper and lower): 50 rpm
Growth zero atmosphere; air growth rate! 50 W/hr Growth time: 12 hours 141 7 The synthesized crystal of two-rings was annealed at 1700° C. for 24 hours to precipitate crystals of hihititanium acid.

φ; Results and Observations A rod-shaped crystal with a diameter of 8 mm and a length of 60 mm was synthesized. A high-quality alexandrite cat's eye in which saponified titanium sword-shaped crystals were precipitated along the 0M length direction was synthesized.

(For example) (11, 9ft of raw material aluminum oxide and lfl of titanium oxide were thoroughly mixed (
, placed in an iridium crucible in an argon or monoatomic atmosphere.
Melt at oso°C and rapidly solidify. 5 of these n
Destroy it.

To this, 122 t% of beryllium oxide and chromium α-f1-chloride (in addition to L2fVr) are thoroughly mixed.

(21 raw material bar production J11!' Example 1 is followed.

(3) Under the crystal synthesis growth conditions, the growth rate was 1 kC15wm7'br and the growth time was t-120 hours. Other conditions are the same as in Example 1.

(4) Annealing <Example 1> Follow K.

(Result 1! A 411-shaped crystal of 8 m x 60 strips in length was synthesized. A high-quality alexandrite cat's eye crystal with TL-shaped titanium oxide crystals precipitated along the growth direction was synthesized.

<Example 3> +11 raw materials, (21 raw materials Keyaki production, (3) conditions for crystal synthesis all follow <Actual tIfA even 2>).

(4) The result of annealing synthesis was annealed at 1200°C for 24R to precipitate titanium oxide crystals. □(5; Result: A rod-shaped crystal with a diameter of 8 squares and a length of 60 squares was synthesized. An alexandrite cat's eye crystal in which IIt-like crystals of saponified titanium were precipitated along the growth direction was synthesized.

・Example 4> The +11 raw material and C (to) raw material rods were prepared in accordance with <Example 1>.

(Example 1 with the crystal synthesis growth direction set as the (010) direction and other conditions
> Follow.

(4) Annealing According to <Example 1>.

Excellent; As a result, crystals in the shape of 4!8 x 40 m and 0 g in length were synthesized. l
! A high-quality alechinandrite cat's eye crystal in which sword-shaped titanium oxide crystals were precipitated along the longitudinal direction was synthesized.

<Example 5> +11 raw materials, (31 raw material rod production according to IM Confucian 1).

(3) Crystal synthesis growth direction (100) direction, other conditions Example 1
> Follow.

(4) Annealing Follow mfAN>.

+151 Result: A rod-shaped crystal with a diameter of 8 cm and a length of 60 cm was synthesized. A high-quality alexandrite cat's eye crystal with needle-shaped titanium oxide crystals precipitated along the growth direction was synthesized.

[Brief explanation of the drawing]

The aR1 diagram is a solid solution state diagram of aluminum oxide and titanium oxide. Applicant Suwa Seikosha Co., Ltd. Agent Patent Attorney Mogami AIaOrTiOa Figure 1 508-

Claims (1)

[Scope of Claims] ... Raw material powder consisting of beryllium oxide, aluminum oxide, iron oxide, chromium oxide, and titanium oxide, which shows the composition ratio of Habo Alexandrite Cat's Eye, is packed into a rubber tube and formed into a rod shape using a rubber press aK, It is sintered into raw material rods. Using this as a raw material, we produce elliptic crystals, alexandrite sintered raw material rods, alexandrite cat's eye crystals,
Alexandrite Kya, 2? Using the Tsuai sintered raw material rod, the well-known FIOating Zone method (hereinafter referred to as 'Fz
method]. The synthesized IiS was heated to 1206°C.
Method for producing artificial alexandrite cat's eye by precipitating titanium aI crystals by annealing at ~1700°C (2) In claim S 1, aluminum oxide =
A solid solution of m-titanium oxide obtained by rapidly cooling and solidifying a molten material consisting of aluminum and titanium oxide is used as a raw material Kll! The method (3) described in the same paragraph, which is characterized by using Claims in which the ratio of beryllium is different from the composition of cliliperyl @1m1
The method for producing human air alexandrite medium yatsutsuai according to item 11. 141 Claims! ! 11R1 section l/nite,
Crystal synthesis by lZf & under H1t0 conditions w! 1. Long speed vertical is α5 w/hr ~ & (Is/hrt4111 and 6
% of the scope of the patent request described in item 1...! How to make ndrite cat's eye.