JPH05178689A - Production of noble metal single crystal - Google Patents

Abstract

PURPOSE:To provide the producing method of noble metal single crystals by which the noble metal single crystals good in quality are easily produced and an ideal crystal face perpendicular to a seed is easily, and accurately formed, and are easy to be handled as a sample for research. CONSTITUTION:The middle of a noble metal wire or an abutting part where two noble metal wires are abutted on each other is heated and melted and simultaneously the noble metal wire is extended toward both end sides to thinly extend the heated and fused part, and a single crystal is allowed to grow. Then, after the single crystal is grown, the thicker part on one side of the wire is gradually heated and fused to produce a single crystal mass 12 in the shape of a large ball. Then, after a seed 13 is welded to the ball-like single crystal mass 12 perpendicularly to the crystal face, the thin part of the noble metal wire is cut and then the ball-like single crystal mass 12 is fused up to a position a little above the central part and solidified downward.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention causes a biochemical reaction in order to investigate the relationship between a noble metal single crystal for catalyst research in consideration of the relationship between the catalyst (ability) and the crystal plane and the relationship between the biochemical reaction and the crystal plane. The present invention relates to a method for producing a noble metal single crystal used for a base plate for a metal.

[0002]

2. Description of the Related Art When a noble metal is melted and solidified, a single crystal is easily generated in a thin portion and a polycrystal is easily formed in a thick portion. Therefore, as shown in FIG. Making crystals. That is, the lower end of the precious metal fine wire 1 is heated and melted to form a molten ball 2, and then the heat source 3 is gradually moved downward from the molten ball 2 to form a single crystal mass 2'of the ball. However, the precious metal fine wire 1 cannot form a large single crystal. So, to make a large single crystal,
As shown in Fig.2, the ball diameter is 2 mm
A large ball 4 was attached, the large ball was heated and melted, and then the heat source 3 was gradually moved downward and solidified. However, the crystal plane formed perpendicular to the seed (noble metal fine wire) 1 is not always the desired plane, and when the large ball 4 is cut with the desired crystal plane, it is biased with respect to the seed 1 as shown in FIG. An inconvenient crystal plane 4 was obtained, and it was difficult to handle as a research sample.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to easily produce a high-quality noble metal single crystal, and to accurately form an ideal crystal plane perpendicular to the seed. An object of the present invention is to provide a method capable of producing a noble metal single crystal that can be easily produced and is easy to handle as a research sample.

[0004]

A method for producing a noble metal single crystal according to the present invention for solving the above-mentioned problems is a noble metal wire in the middle or two noble metal wires are butted and the butted portion is heated and melted. By pulling to the both ends to thinly draw the heated and melted part, grow a single crystal, and then grow the single crystal, and gradually heat and melt one thick part of the precious metal wire to create a single crystal mass of a large ball. Then, a seed is welded perpendicularly to the desired crystal plane on the single crystal ingot of this ball, then the thin part of the precious metal wire is cut, and then the single crystal ingot of the ball is melted slightly above the central part, It is characterized by solidifying toward.

[0005]

As described above, in the method for producing a noble metal single crystal of the present invention, a thick noble metal wire is heated and melted in the middle, and the noble metal wire is pulled toward both ends to thinly draw the heated and melted portion to grow a single crystal. Therefore, a good quality single crystal can be obtained in this thin portion. Next, one thick part of the noble metal wire is gradually heated and melted to form a large ball single crystal ingot, and this single crystal ingot is obtained by extending and growing the above-mentioned high quality single crystal as it is. . Then, a seed is welded to the single crystal ingot of the ball perpendicularly to the crystal plane, the thin portion of the precious metal wire is cut, and then the single crystal ingot of the ball is melted to slightly above the central portion, and then downward. Since it solidifies toward the seed, the desired crystal plane of the seed is formed perpendicularly to the single crystal ingot of the ball.

[0006]

Example 1 An example of a method for producing a noble metal single crystal of the present invention will be described with reference to the drawings. As shown in FIG.
The Pt wire 10 was heated and melted in the middle, and the Pt wire 10 was pulled toward both ends to stretch the heat-melted portion 11 to a minimum diameter of 0.9 mm to grow a single crystal. Next, after the single crystal growth, one thick portion of the Pt wire 10 was gradually heated and melted to prepare a large ball single crystal mass 12 having a spherical diameter of 4 mm as shown in FIG. Then, as shown in FIG. 3, a thin seed (Pt wire) 13 having a wire diameter of 1 mm is welded to the single crystal ingot 12 of the ball so as to be perpendicular to the desired crystal plane based on the facet 12a, and then Pt.
The line 10 was cut off at the narrow part as shown in FIG. After that, the seed 13 is grasped, and the single crystal mass 12 of the ball is faced down.
As shown in (1), the single crystal lump 12 was melted to a position slightly above the center and solidified downward as shown in FIG. As a result, desired high quality crystal planes were formed perpendicularly to the seeds 13 in the ball single crystal mass 12 '.

[0007]

[Embodiment 2] As shown in FIG. 6, a Pt wire 14 having a wire diameter of 2 mm and a Pt wire 15 having a wire diameter of 1 mm are butted and heated and melted so that the butted portions are fused, and then as shown in FIG.
After growing the Pt wire 15 side having a diameter of 2 mm to a diameter of 2 mm, stretching it to 0.8 mm and growing it for 10 mm, a spherical single crystal mass 16 having a diameter of 4 mm was prepared as shown in FIG. Then, based on the grown (III) facet 16a, the crystal growth direction is set by the laser beam method so that the desired crystal plane becomes vertical, and as shown in FIG. 9 again, the single crystal ingot 16 is grown and the seed is easily welded. For this purpose, a single crystal ingot 16 'was made thin. Next, as shown in FIG. 10, after welding a seed (Pt wire) 17 of 1 mm, the Pt wire 15
I cut it off with a thin part. After that, the seed 17 was gripped, and the single crystal ingot 16 'was erected straight up as shown in FIG. 11, the single crystal ingot 16' was melted slightly above the central portion, and solidified downward. . As a result, a high-quality crystal plane was formed perpendicularly to the seed 17 in a ball single crystal mass 16 ″.

When the thus obtained single crystal ingot 12 is used as a research sample, the single crystal ingot 12 is cut perpendicularly to the seed 13 and the cut surface is polished to a good quality crystal plane. Thus, a Pt single crystal for catalyst research and a Pt single crystal for biosynthesis students which are easy to handle and can be scrutinized can be obtained.

[0009]

As described above, according to the method for producing a noble metal single crystal of the present invention, a good quality noble metal single crystal plane can be easily formed, and an ideal crystal plane perpendicular to the seed is provided. Therefore, it is possible to easily produce a noble metal single crystal which is easy to handle and can be scrutinized for catalytic research or for inducing biochemical reaction.

[Brief description of drawings]

FIG. 1 is a diagram showing steps of an example of a method for producing a noble metal single crystal of the present invention.

FIG. 2 is a diagram showing steps of an embodiment of a method for producing a noble metal single crystal of the present invention.

FIG. 3 is a diagram showing steps of one embodiment of the method for producing a noble metal single crystal of the present invention.

FIG. 4 is a diagram showing steps of an example of a method for producing a noble metal single crystal of the present invention.

FIG. 5 is a diagram showing steps of an example of a method for producing a noble metal single crystal of the present invention.

FIG. 6 is a diagram showing steps of another embodiment of the method for producing a noble metal single crystal of the present invention.

FIG. 7 is a diagram showing steps of another embodiment of the method for producing a noble metal single crystal of the present invention.

FIG. 8 is a diagram showing steps of another embodiment of the method for producing a noble metal single crystal of the present invention.

FIG. 9 is a diagram showing steps of another embodiment of the method for producing a noble metal single crystal of the present invention.

FIG. 10 is a diagram showing a step of another example of the method for producing a noble metal single crystal of the present invention.

FIG. 11 is a diagram showing a step of another example of the method for producing a noble metal single crystal of the present invention.

FIG. 12 is a diagram showing a conventional method for producing a noble metal single crystal.

FIG. 13 is a diagram showing another conventional method for producing a noble metal single crystal.

14 is a diagram showing a state in which a noble metal single crystal obtained by the manufacturing method of FIG. 7 is cut at a desired crystal plane.

[Explanation of symbols]

 10 Noble metal wire (Pt wire) 11 Heating / melting part 12, 16 ', 16 ″ Single crystal ingot 12a, 16a Facet 13, 17 Seed 14, 15 Pt wire 16 Spherical single crystal ingot

Claims (1)

[Claims] 1. A noble metal wire or two noble metal wires are butted against each other, the butted parts are heated and melted, and the noble metal wires are pulled toward both ends to thinly draw the heated and melted parts to grow a single crystal. After the single crystal growth, one thick part of the noble metal wire is gradually heated and melted to form a large ball single crystal mass, and then a seed is welded to the single crystal mass of this ball perpendicular to the crystal plane. A method for producing a noble metal single crystal, which comprises cutting a thin part of a noble metal wire, and then melting a single crystal mass of a ball to a position slightly above the central part and solidifying downward.