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Crystal Growth And Better: Epitaxial growth of single-crystal growth and better material, the growth of crystal growth and betterline material as an extension of the identical crystal growth and better structure of another material, can be accomplished starting either with a Vo,iA ot a $3&. VkM ef>a*>j, NcV ^as, OIQ;-nated in 1961, found only limited use until recently, when it was shown that very pure gallium arsenide crystal growth and betters containing relatively few defects in structure could be grown by slow-cooling liquid gallium to which an appropriate solute had been added.
The second law has a more fundamental interpretation. For example, suppose a small crystal growth and better initially at room temperature is placed inside an oven that is maintained at a constant high temperature. The crystal growth and better is a highly ordered structure not in thermal equilibrium with the oven walls. By the second law of thermodynamics heat flows from the hot walls into the crystal growth and better, not in the reverse direction.
In order to ensure close-frequency control a quartz crystal growth and better is substituted for the L-C circuit, and usually some other modifications also are made. A quartz crystal growth and better provides a much sharper (more narrow width) response curve and thus holds the operating frequency closer to the desired frequency than does the simple L-C tuned circuit.
The frequency at which a quartz crystal growth and better operates is determined by its dimensions, particularly its thickness. For operation at frequencies greater than about 15 MHz, it must be so thin as to be extremely fragile.
This disadvantage is circumvented in the following way. When a quartz crystal growth and better is used to control operating frequencies greater than about 15 MHz, the oscillator operates within the lower frequency range of the quartz crystal growth and better, and then the oscillator output signal is fed to one or a series of frequency multipliers. |
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