2.3.3.3.45. NXbias_spectroscopy¶
Status:
base class (contribution), extends NXobject
Description:
A base class for bias spectroscopy to describe the change in the physical proper ...
A base class for bias spectroscopy to describe the change in the physical properties of the sample with respect to the sweep voltage applied on a sample of STM/AFM/… experiment.
In these experiments an electric potential is applied between the (conductive) sample and the probe (tip), and the physical properties (e.g. tunnelling current) is measured as the function of this potential. The potential is varied in so-called voltage sweeps and the corresponding properties are recorded accordingly.
Symbols:
No symbol table
- Groups cited:
NXcircuit, NXdata, NXobject, NXpositioner_spm, NXscan_control
Structure:
measurement_type: (optional) NX_CHAR
The measurement of the I(V) curve can come in two ways: ...
The measurement of the I(V) curve can come in two ways: 1. Constant spacing: The bias voltage is swept from the start to the end with a constant spacing between the tip and surface. 2. Variable spacing: The bias voltage is swept from the start to the end in a discretized spacing between the tip and surface. (Either an array of voltages, or the steps are defined).
Any of these values:
constant_spacing|variadic_spacingPOSITIONER_SPM: (optional) NXpositioner_spm
The PID (proportional, integral, differential feedback system) positioner info ...
The PID (proportional, integral, differential feedback system) positioner information while running bias voltage-tunneling current measurement.
These components position the probe relative to the sample, thus help obtaining maps of the data across the sample surface.
z_offset: (optional) NX_NUMBER {units=NX_LENGTH} ⤆
The z-offset is a starting tip position before the sweep starts (typically t ...
The z-offset is a starting tip position before the sweep starts (typically the position of a piezo element).
CIRCUIT: (optional) NXcircuit
acquisition_time: (optional) NX_NUMBER {units=NX_TIME} ⤆
The time or period is taken by a bias sweep to acquire the data for ...
The time or period is taken by a bias sweep to acquire the data for a single bias sweep point (when the given point or whole sweep is started.).
animation_time: (optional) NX_NUMBER {units=NX_TIME}
The time or period is taken by a bias sweep to be displayed.
measurement_time: (optional) NX_NUMBER {units=NX_TIME}
The time or period is taken by the circuit to measure a full bias sweep volt ...
The time or period is taken by the circuit to measure a full bias sweep voltage or bias current. (duration of the measurement)
indicators_period: (optional) NX_NUMBER {units=NX_TIME}
The time or period is taken by the circuit to indicate the bias sweep voltag ...
The time or period is taken by the circuit to indicate the bias sweep voltage after measuring the voltage.
bias_sweep: (optional) NXscan_control
The bias sweep scan which is is performed in the scanning probe microscopy ...
The bias sweep scan which is is performed in the scanning probe microscopy experiments.
scan_type: (optional) NX_CHAR ⤆
The type of scan like mesh, spiral, etc. ...
The type of scan like mesh, spiral, etc.
This combines not only how the voltages are changed, but how the voltage values are correlated to a position across the sample surface, measuring sweeps are each spatial coordinate or mapping the response at constant voltage, etc. For STS experiment, the scan type is usually a single-point scan (trajectory scan).
Obligatory value:
linearsweep_number: (optional) NX_NUMBER
The number of sweeps taken during the bias spectroscopy.
first_settling_time: (optional) NX_NUMBER {units=NX_TIME}
The initial time is taken to settle the bias voltage at the desired value. ...
The initial time is taken to settle the bias voltage at the desired value. On each sweep usually, the system takes time to settle to the bias voltage at the next value.
end_settling_time: (optional) NX_NUMBER {units=NX_TIME}
The time is taken to settle the bias voltage at the desired value. ...
The time is taken to settle the bias voltage at the desired value. The time (at the last sweep) to settle for the last value of the sweep.
settling_time: (optional) NX_NUMBER {units=NX_TIME}
The time is taken to settle the bias voltage at the desired value. On each s ...
The time is taken to settle the bias voltage at the desired value. On each sweep usually, the system takes time to settle the bias voltage at the next value.
max_slew_rate: (optional) NX_NUMBER {units=NX_ANY}
The rate at which the amplifier responds to the voltage change ...
The rate at which the amplifier responds to the voltage change (to reach at the desired value). It defines if the tip movement and voltage sweep are synchronized.
final_z: (recommended) NX_NUMBER
The z position after the sweeps are done.
total_spectroscopy_time: (recommended) NX_NUMBER {units=NX_TIME}
The total time needed for the entire voltage sweep.
scan_region: (optional) NXobject ⤆
The scan region is the area of phase space or sub-phase space where the scan ...
The scan region is the area of phase space or sub-phase space where the scan is performed.
scan_offset_bias: (optional) NX_NUMBER {units=NX_VOLTAGE} ⤆
The starting voltage of the bias sweep. The range of voltages for the swee ...
The starting voltage of the bias sweep. The range of voltages for the sweep can be defined with scan voltage offset and scan voltage range (difference between minimum and maximum voltage values in a sweep)
scan_range_bias: (optional) NX_NUMBER {units=NX_VOLTAGE} ⤆
The range of voltages for the sweep can be defined with scan voltage offse ...
The range of voltages for the sweep can be defined with scan voltage offset and scan voltage range (difference between minimum and maximum voltage values in a sweep)
scan_start_bias: (optional) NX_NUMBER {units=NX_VOLTAGE} ⤆
The start of the bias scan voltage.
scan_end_bias: (optional) NX_NUMBER {units=NX_VOLTAGE} ⤆
The end value of the bias scan voltage.
linear_sweep: (optional) NXobject ⤆
In the linear sweep, the bias voltage is changed linearly from the start val ...
In the linear sweep, the bias voltage is changed linearly from the start value to the end value.
backward_sweep: (optional) NX_BOOLEAN
If the bias voltage sweep is also performed in the opposite direction.
scan_points_bias: (optional) NX_NUMBER ⤆
The number of voltage points per sweep.
step_size_bias: (optional) NX_NUMBER {units=NX_VOLTAGE} ⤆
The step size between the two consecutive bias voltage values during the sweep.
scan_time: (optional) NX_NUMBER {units=NX_TIME}
The time taken by the scanner to scan the entire area.
reset_bias: (optional) NX_BOOLEAN
The reset_bias defines whether the bias voltage should be reset to the sta ...
The reset_bias defines whether the bias voltage should be reset to the starting value after the sweep is completed.
SCAN_data: (optional) NXdata ⤆
The scan data is the data collected during the scan. ...
The scan data is the data collected during the scan. If the scan has several channels or derivatives from the channel data, please duplicate this NXdata group for each.
Hypertext Anchors¶
List of hypertext anchors for all groups, fields, attributes, and links defined in this class.
/NXbias_spectroscopy/bias_sweep/linear_sweep/backward_sweep-field
/NXbias_spectroscopy/bias_sweep/linear_sweep/reset_bias-field
/NXbias_spectroscopy/bias_sweep/linear_sweep/SCAN_data-group
/NXbias_spectroscopy/bias_sweep/linear_sweep/scan_points_bias-field
/NXbias_spectroscopy/bias_sweep/linear_sweep/scan_time-field
/NXbias_spectroscopy/bias_sweep/linear_sweep/step_size_bias-field
/NXbias_spectroscopy/bias_sweep/scan_region/scan_end_bias-field
/NXbias_spectroscopy/bias_sweep/scan_region/scan_offset_bias-field
/NXbias_spectroscopy/bias_sweep/scan_region/scan_range_bias-field
/NXbias_spectroscopy/bias_sweep/scan_region/scan_start_bias-field
/NXbias_spectroscopy/bias_sweep/total_spectroscopy_time-field
