Our cryostat is capable of reaching liquid helium temperatures as low as 4K. Typically, however, we use liquid nitrogen as the sole refrigerant for our experiments, which provides as low as 77K for the sample environment. The Oxford Maglab cryostat is capable of automatic cycling of temperature through a custom Igor Pro programmed controller.
Trends in temperature variation allow for the examination of energy states by current-voltage measurements as well as capacitance-voltage experiments. Fitting parameters to J-V curves also allows for matching of thermal properties to electron transport models.
The cryostat allows for a nitrogen gas or vacuum environment, important for oxygen-sensitive devices. The sample probe uses a Xenon arc lamp as a light source for both light and dark J-V curves.