Floating-Zone Melting Apparatus with Multi-Directional Infrared Heating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional floating zone melting apparatuses face challenges in growing single crystals with large diameters due to uneven temperature distribution and infrared ray absorption, leading to unstable molten solutions and contamination from skull crucibles, while also incurring high loads on infrared lamps.
Innovation Solution
A floating zone melting apparatus with a sample chamber made of transparent quartz, using a combination of downward and upward infrared irradiation means disposed at regular intervals around the sample, along with independent position control mechanisms for the irradiation means and a sample heating mechanism to maintain consistent temperature and prevent contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If infrared lamps are used to heat and melt the sample in conventional floating zone melting apparatuses, then the sample can be molten and deposited without using a container, but the infrared lamps bear extremely large loads and cannot stably melt samples with large diameters
Solution Approach 1:
The single infrared lamp is divided into multiple infrared lamps (at least three) arranged around the sample. Each lamp handles a portion of the heating load, distributing the power requirements and enabling stable melting of large diameter samples without overloading individual lamps.
Solution Approach 2:
The heating approach transitions from a single-point or single-direction infrared source to a multi-directional arrangement where infrared lamps are positioned around the sample in different spatial locations, providing omnidirectional heating that evenly melts large diameter samples.
2Temperature
If infrared rays are concentrated on the sample from a single direction, then the apparatus structure is simple, but uneven temperature distribution occurs on the sample surface
Solution Approach 1:
The single-direction irradiation system is segmented into multiple irradiation sources positioned at different locations around the sample. This multi-source arrangement creates overlapping heating zones that eliminate temperature gradients and achieve uniform temperature distribution across the sample surface.
3Reliability
If skull crucibles are used to hold the sample material, then the sample can be contained during melting, but skull crucible material is incorporated into the crystal as impurity
Solution Approach 1:
The sample material itself serves as the heating medium through direct infrared absorption, eliminating the need for external crucibles. The multi-directional infrared lamps heat the sample from all sides, allowing containerless melting while maintaining crystal purity by preventing skull crucible material contamination.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables stable melting and growth of single crystals with large diameters by improving temperature distribution and reducing infrared lamp load, ensuring high-quality crystals with uniform composition and reduced contamination.
Implementation Method 1
irradiating a sample with an infrared ray to heat and melt the sample
Implementation Method 2
infrared rays emitted from an infrared lamp unit are converged to the other focal point
Implementation Method 3
the molten sample is solidified on a seed crystal or the like to grow a single crystal
Data Source
Figure 1
Figure 2
Figure 3
AI summary
[Abstract] This invention provides a floating zone melting apparatus in which a sample rod especially having a large diameter can be stably melted with a certainty and the crystal being grown can retain a flat shape at the interface of the solid phase and the liquid phase, whereby a single crystal having a large diameter can be grown. [Problem] It is an object to provide a floating zone melting apparatus of the infrared concentration heating type in which a sample is set in a sample chamber made of a transparent quartz tube, an atmospheric gas is introduced into the sample chamber, infrared rays emitted from a plurality of infrared ray irradiation means are converged to the sample to heat and melt the sample in this state, thereby obtaining a melt, and the melt is solidified on a seed crystal to grow a single crystal. The plurality of infrared ray irradiation means comprise a plurality of infrared ray irradiation means of the downward irradiation type that emit an infrared ray downward from an oblique upper direction and a plurality of infrared ray irradiation means of the upward irradiation type that emit an infrared ray upward from an oblique lower direction.