The present disclosure provides a growth method of a high-temperature phase lanthanum borosilicate crystal, where the high-temperature phase lanthanum borosilicate crystal is a β-La.sub.1-yLn.sub.yBSiO.sub.5 crystal prepared by a high-temperature flux method; a composite flux system is (La.sub.1-yLn.sub.y)BO.sub.3—LiMoO.sub.4—SiO.sub.2—B.sub.2O.sub.3, and (La.sub.1-yLn.sub.y)BO.sub.3, LiMoO.sub.4, SiO.sub.2, and B.sub.2O.sub.3 in the system have molar percentages of x.sub.1, x.sub.2, x.sub.3, and x.sub.4, respectively; 0<x.sub.1<0.3, 0.7≤x.sub.2<1, 0<x.sub.3<0.3, x.sub.1+x.sub.2+x.sub.3=1, x.sub.1:x.sub.4=2:1 to 4:1. In the present disclosure, a difficulty is overcome in the crystal growth of β-LaBSiO.sub.5 due to phase transition. The crystal is an optical function material that does not undergo the phase transition during annealing and can exist stably at room temperature. The crystal is widely used in laser, terahertz, and other fields.

The present invention provides a PZN-based large-size ternary high-performance single crystal, a growing method and a molten salt furnace. The PZN-based large-size ternary high-performance single crystal is represented by formula (1-x-y)Pb(B′.sub.1/2B″.sub.1/2)O.sub.3-yPb(Zn.sub.1/3Nb.sub.2/3)O.sub.3-xPbTiO.sub.3, wherein B′ is Mg, Fe, Sc, Ni, In, Yb, Lu and/or Ho, B″ is Nb, Ta and/or W, 0.4<x<0.6, 0.1<y<0.4, 0.1<1-x-y<0.4. The present invention adjusts the convective change of the melt through the rotation of the top seed and the bottom crucible, overcoming the problems of serious crystal inclusions and poor crystal quality during the growth process, and can adapt the change of the crystal diameter to the thermal inertia of the heat preservation system, thus effectively reducing crystal inclusions and improving the yield of the crystal.

Provided is a method for producing a SiC single crystal wherein a 4H—SiC single crystal is grown by minimizing generation of polytypes other than 4H. A method for producing a SiC single crystal by a solution process, wherein a seed crystal is 4H—SiC, and a (000-1) face of the seed crystal is a growth surface, wherein the method includes: setting a temperature at a center section of a region of a surface of a Si—C solution where the growth surface of the seed crystal contacts to 1900° C. or higher, and limiting a ΔTc/ΔTa to 1.7 or greater, wherein the ΔTc/ΔTa is a ratio of a temperature gradient ΔTc between the center section and a location 10 mm below the center section in the vertical direction, with respect to a temperature gradient ΔTa between the center section and a location 10 mm from the center section in the horizontal direction.

A low-resistance p-type SiC single crystal containing no inclusions is provided. A method for producing a SiC single crystal in which a SiC seed crystal substrate is contacted with a Si—C solution having a temperature gradient such that a temperature of the Si—C solution decreases from an interior of the Si—C solution toward a surface of the Si—C solution, to grow the SiC single crystal, wherein the Si—C solution comprises Si, Cr, Al and B, and wherein the Al is comprised in the Si—C solution in an amount of 10 at % or greater, based on the total of the Si, Cr, Al and B, and the B is comprised in the Si—C solution in an amount of greater than 0.00 at % and no greater than 1.00 at %, based on the total of the Si, Cr, Al and B.

Systems and methods for perovskite single crystal growth include using a low temperature solution process that employs a temperature gradient in a perovskite solution in a container, also including at least one small perovskite single crystal, and a substrate in the solution upon which substrate a perovskite crystal nucleates and grows, in part due to the temperature gradient in the solution and in part due to a temperature gradient in the substrate. For example, a top portion of the substrate external to the solution may be cooled.

An object of the present invention is to provide a SIC single crystal production apparatus that stirs and heats a Si—C solution easily. The apparatus includes a crucible capable of containing a Si—C solution, a seed shaft, and an induction heater. The crucible includes a tubular portion and a bottom portion. The tubular portion includes an outer peripheral surface and an inner peripheral surface. The bottom portion is disposed at a lower end of the tubular portion. The bottom portion defines an inner bottom surface of the crucible. The outer peripheral surface includes a groove extending in a direction crossing the circumferential direction of the tubular portion.

The provided by the disclosure is a SiC single crystal production method permitting suppression of temperature variation of a Si—C solution even in a case of long-time crystal growth. The SiC single crystal production method includes: a preparation step of preparing a production apparatus including a crucible, a seed shaft, and an internal lid; a formation step of heating the material in the crucible to form the Si—C solution; a growth step of bringing the seed crystal into contact with the Si—C solution to produce the Si—C single crystal on the seed crystal; an internal lid adjustment step of vertically moving one of the internal lid and the crucible relative to the other during the growth step to keep an amount of variation in vertical distance between the internal lid and the Si—C solution within a first reference range.

Provided are an SiC single-crystal ingot containing an SiC single crystal having a low threading dislocation density and low resistivity; an SiC single crystal; and a production method for the SiC single crystal. The SiC single crystal ingot contains a seed crystal and a grown crystal grown by a solution process in which the seed crystal is the base point, the grown crystal of the SiC single crystal ingot containing a nitrogen density gradient layer in which the nitrogen content increases in the direction of growth from the seed crystal.

A low-resistance p-type SiC single crystal containing no inclusions is provided. This is achieved by a method for producing a SiC single crystal wherein a SiC seed crystal substrate 14 is contacted with a Si—C solution 24 having a temperature gradient in which the temperature falls from the interior toward the surface, to grow a SiC single crystal, and wherein the method comprises: using, as the Si—C solution, a Si—C solution containing Si, Cr and Al, wherein the Al content is 3 at % or greater based on the total of Si, Cr and Al, and making the temperature gradient y (° C./cm) in the surface region of the Si—C solution 24 satisfy the following formula (1): y≧0.15789x+21.52632 (1) wherein x represents the Al content (at %) of the Si—C solution.

A method and apparatus for manufacturing an SiC single crystal includes a graphite crucible for receiving an SiC solution with first and second induction heating coils wound around it. The first induction heating coil is located higher than the surface of the SiC solution. The second induction heating coil is located lower than the first induction heating coil. A power supply supplies a first alternating current to the first induction heating coil and supplies, to the second induction heating coil, a second alternating current having the same frequency as the first alternating current and flowing in the direction opposite to that of the first alternating current. The distance between the surface of the SiC solution and the position in the portion of the side wall of the crucible in contact with the SiC solution with the strength of a magnetic field at its maximum satisfies a predetermined equation.