| CuHallData {complexlm} | R Documentation |
AC (Complex) Hall effect data measured from a thin-film copper sample.
Description
This data serves as a 'real-world' example of complex valued measurements that can be analyzed by the methods contained in 'complexlm'. The Hall effect is a perpendicular (to the magnetic field and current) voltage that appears across an electrically conductive material when it is placed in an external magnetic field. It is commonly used to determine the mobility and density of charge carriers (electrons and/or holes) within materials.
Usage
CuHallData
Format
A dataframe with 240 rows and 11 columns. Most names contain the units of the column after the last or second to last period.
Details
The AC Hall effect is a more advanced technique that uses a time varying (sinusoidal) magnetic field and lock-in voltage measurement. The measured output signal is thus a wave, and best described by complex numbers. This strategy drastically lowers the noise floor, enabling measurement of difficult, low-mobility, materials.
This data was take at room temperature in a vacuum chamber using a custom built and programmed system. A Keithley 2636 sourcemeter provided the excitation current, while an SRS 830 lock-in amplifier measured the voltage signal from the sample. The sample consisted of a 0.8 mm square of 1000 Angstroms thick evaporated copper film on a 1.5 centimeter square die of oxidized crystalline silicon.
The variables included in the dataframe are as follows:
- Temperature.K.
The temperature of the sample during this measurement. Units of Kelvin.
- Magnet.Field.Frequency.Hz.
The frequency of the oscillating magnetic field used for this measurement. Units are Hertz.
- Magnetic.Field.T.
The amplitude of the magnetic field during this measurement. Units of Tesla.
- Contact.Arrangement
This measurement involves four electrical contacts (current in and out, and voltage hi and lo), placed at the corners. Corresponding contacts must be opposite each other, so there are two possible arrangements: "D" and "F".
- Current.Set.A.
The desired current to be sent through the sample for this measurement. There was an error in recording beyond the 8th row. Units of Amperes.
- Current.In.meas.A.
The current measured leaving the sourcemeter, towards the sample. Units of Amperes.
- Current.Out.meas.A.
The current measured exiting the sample. Units of Amperes.
- Source.V.V.
The voltage generated across the sample in order to produce the desired current. Units of Volts.
- OutputV
The complex voltage measured across the sample. Ideally proportional to the current and magnetic field. Units of Volts.
- Current.leak
The difference between the input and output currents. Units of Amperes.
- Resistivity.Ohm.cm
The resistivity of the sample as calculated by the Van Der Pauw method from previous DC current-voltage sweeps. Units of Ohm*centimeter.
- thickness.cm.
The thickness of the copper film in centimeters.
Author(s)
William Ryan wryan1@binghamton.edu