Which process involves using a heating unit to create a synthetic crystal from a rotating solid rod of chemicals?

The process of pulling refers to the creation of synthetic crystals through the controlled melting and crystallization of materials, specifically by using a technique that involves drawing or "pulling" a solid rod of chemicals from a molten mixture. This method, often associated with the Czochralski process, allows for the formation of high-quality single crystals by rotating the rod as it is pulled from the melt, helping to ensure a uniform and consistent structure in the resulting crystal.

In contrast, the other methods involve different techniques for crystal growth. Flame fusion typically involves melting chemicals to form crystals but does not use the solid rod technique; instead, it uses a flame to melt material, which then crystallizes upon cooling. Floating zone is a method that creates crystals by melting a small zone of a solid rod in a vacuum or inert atmosphere, allowing for the crystal growth as the molten zone moves along the rod. Hydrothermal growth uses high-pressure and high-temperature conditions in water to crystallize materials, which differs significantly from the pulling technique.