The disclosure relates to a semimetal compound of Pt and a method for making the same. The semimetal compound is a single crystal material of PtSe.sub.2. The method comprises: providing a PtSe.sub.2 polycrystalline material; placing the PtSe.sub.2 polycrystalline material in a reacting chamber; placing chemical transport medium in the reacting chamber; evacuating the reacting chamber to be vacuum less than 10 Pa; placing the reacting chamber at a temperature gradient, wherein the reacting chamber has a first end at a temperature of 1200 degrees Celsius to 1000 degrees Celsius and a second end opposite to the first end and at a temperature of 1000 degrees Celsius to 900 degrees Celsius; and keeping the reacting chamber in the temperature gradient for 10 days to 30 days.

The disclosure relates to a semimetal compound of Pt and a method for making the same. The semimetal compound is a single crystal material of PtSe.sub.2. The method comprises: providing a PtSe.sub.2 polycrystalline material; placing the PtSe.sub.2 polycrystalline material in a reacting chamber; placing chemical transport medium in the reacting chamber; evacuating the reacting chamber to be vacuum less than 10 Pa; placing the reacting chamber at a temperature gradient, wherein the reacting chamber has a first end at a temperature of 1200 degrees Celsius to 1000 degrees Celsius and a second end opposite to the first end and at a temperature of 1000 degrees Celsius to 900 degrees Celsius; and keeping the reacting chamber in the temperature gradient for 10 days to 30 days.

The disclosure relates to a method for making semimetal compound of Pt. The semimetal compound is a single crystal material of PtSe.sub.2. The method comprises: placing pure Pt and pure Se in a reacting chamber as reacting materials; evacuating the reacting chamber to be vacuum less than 10 Pa; heating the reacting chamber to a first temperature of 600 degrees Celsius to 800 degrees Celsius and keeping for 24 hours to 100 hours; cooling the reacting chamber to a second temperature of 400 degrees Celsius to 500 degrees Celsius at a cooling rate of 1 degrees Celsius per hour to 10 degrees Celsius per hour and keeping for 24 hours to 100 hours to obtain a crystal material of PtSe.sub.2; and separating the excessive reacting materials from the crystal material of PtSe.sub.2.

The disclosure relates to a method for making semimetal compound of Pt. The semimetal compound is a single crystal material of PtSe.sub.2. The method comprises: placing pure Pt and pure Se in a reacting chamber as reacting materials; evacuating the reacting chamber to be vacuum less than 10 Pa; heating the reacting chamber to a first temperature of 600 degrees Celsius to 800 degrees Celsius and keeping for 24 hours to 100 hours; cooling the reacting chamber to a second temperature of 400 degrees Celsius to 500 degrees Celsius at a cooling rate of 1 degrees Celsius per hour to 10 degrees Celsius per hour and keeping for 24 hours to 100 hours to obtain a crystal material of PtSe.sub.2; and separating the excessive reacting materials from the crystal material of PtSe.sub.2.

The disclosure relates to a method for making semimetal compound of Pt. The semimetal compound is a single crystal material of PtSe.sub.2. The method comprises: placing pure Pt and pure Se in a reacting chamber as reacting materials; evacuating the reacting chamber to be vacuum less than 10 Pa; heating the reacting chamber to a first temperature of 600 degrees Celsius to 800 degrees Celsius and keeping for 24 hours to 100 hours; cooling the reacting chamber to a second temperature of 400 degrees Celsius to 500 degrees Celsius and keeping for 24 hours to 100 hours at a cooling rate of 1 degrees Celsius per hour to 10 degrees Celsius per hour to obtain a crystal material of PtSe.sub.2; and separating the excessive reacting materials from the crystal material of PtSe.sub.2.

The disclosure relates to a method for making semimetal compound of Pt. The semimetal compound is a single crystal material of PtSe.sub.2. The method comprises: placing pure Pt and pure Se in a reacting chamber as reacting materials; evacuating the reacting chamber to be vacuum less than 10 Pa; heating the reacting chamber to a first temperature of 600 degrees Celsius to 800 degrees Celsius and keeping for 24 hours to 100 hours; cooling the reacting chamber to a second temperature of 400 degrees Celsius to 500 degrees Celsius and keeping for 24 hours to 100 hours at a cooling rate of 1 degrees Celsius per hour to 10 degrees Celsius per hour to obtain a crystal material of PtSe.sub.2; and separating the excessive reacting materials from the crystal material of PtSe.sub.2.

A method for producing a SiC single crystal with few dislocations and defects and a large diameter enlargement ratio is provided. A method for producing a SiC single crystal by solution process, wherein a bottom face of a seed crystal is (0001) or (000-1) face and has circular shape with at least a partially removed section and a circular arc-shaped section on an outer periphery, the number of the removed sections is one or more, shapes of the removed sections are bow-shaped with a minor arc or semi-circumference removed along a chord connecting two points on the circular arc, a central angle formed by a center of the circular shape and the two points is 40 or greater, and a total of the central angles of the removed sections is no greater than 180, the method comprising forming a meniscus and growing the single crystal from the bottom face.

A method for producing a SiC single crystal with few dislocations and defects and a large diameter enlargement ratio is provided. A method for producing a SiC single crystal by solution process, wherein a bottom face of a seed crystal is (0001) or (000-1) face and has circular shape with at least a partially removed section and a circular arc-shaped section on an outer periphery, the number of the removed sections is one or more, shapes of the removed sections are bow-shaped with a minor arc or semi-circumference removed along a chord connecting two points on the circular arc, a central angle formed by a center of the circular shape and the two points is 40 or greater, and a total of the central angles of the removed sections is no greater than 180, the method comprising forming a meniscus and growing the single crystal from the bottom face.

A silicon-based molten composition according to an exemplary embodiment is used for a solution growth method for forming a silicon carbide single crystal, and represented by Formula 1 including silicon (Si), a first metal M1, a second metal M2 and a third metal M3, wherein the first metal M1 is one or more selected from the group consisting of nickel (Ni) and manganese (Mn), the second metal M2 is one or more selected from the group consisting of scandium (Sc) and titanium (Ti), and the third metal M3 is one or more selected from the group consisting of aluminum (Al) and gallium (Ga):

Si.sub.aM1.sub.bM2.sub.cM3.sub.dFormula 1 wherein a is 0.3 to 0.8, b is 0.1 to 0.5, c is 0.01 to 0.3, d is 0.01 to 0.2, and a+b+c+d is 1.

A silicon-based molten composition according to an exemplary embodiment is used for a solution growth method for forming a silicon carbide single crystal, and represented by Formula 1 including silicon (Si), a first metal M1, a second metal M2 and a third metal M3, wherein the first metal M1 is one or more selected from the group consisting of nickel (Ni) and manganese (Mn), the second metal M2 is one or more selected from the group consisting of scandium (Sc) and titanium (Ti), and the third metal M3 is one or more selected from the group consisting of aluminum (Al) and gallium (Ga):

Si.sub.aM1.sub.bM2.sub.cM3.sub.dFormula 1 wherein a is 0.3 to 0.8, b is 0.1 to 0.5, c is 0.01 to 0.3, d is 0.01 to 0.2, and a+b+c+d is 1.