MFM (HEAD)

MFM — Magnetic force microscopy

Functions

void	gwy_data_field_mfm_perpendicular_stray_field ()
void	gwy_data_field_mfm_perpendicular_stray_field_angle_correction ()
void	gwy_data_field_mfm_perpendicular_medium_force ()
void	gwy_data_field_mfm_shift_z ()
gdouble	gwy_data_field_mfm_find_shift_z ()
void	gwy_data_field_mfm_parallel_medium ()
void	gwy_data_field_mfm_current_line ()

Types and Values

enum	GwyMFMProbeType
enum	GwyMFMComponentType
enum	GwyMFMGradientType

Includes

#include <libprocess/gwyprocess.h>

Description

Functions

gwy_data_field_mfm_perpendicular_stray_field ()

void
gwy_data_field_mfm_perpendicular_stray_field
                               (GwyDataField *mfield,
                                GwyDataField *out,
                                gdouble height,
                                gdouble thickness,
                                gdouble sigma,
                                gboolean walls,
                                gdouble wall_delta);

Calculates stray field for perpendicular media, based on a mask showing the magnetisation orientation.

Parameters

mfield	Mask representing the magnetisation orientation.
out	Target data field to put the result to. It will be resized to match mfield .
height	Height above the surface.
thickness	Film thickness.
sigma	Magnetic charge.
walls	Include domain walls.
wall_delta	Domain wall thickness

Since: 2.51

gwy_data_field_mfm_perpendicular_stray_field_angle_correction ()

void
gwy_data_field_mfm_perpendicular_stray_field_angle_correction
                               (GwyDataField *field,
                                gdouble angle,
                                GwyOrientation orientation);

Performs correction of magnetic data for cantilever tilt.

Parameters

field	Field to be processed. It will be changed by the correction.
out	Cantilever angle in degrees.
orientation	Cantilever orientation with respect of the data.

Since: 2.54

gwy_data_field_mfm_perpendicular_medium_force ()

void
gwy_data_field_mfm_perpendicular_medium_force
                               (GwyDataField *hz,
                                GwyDataField *fz,
                                GwyMFMProbeType type,
                                gdouble mtip,
                                gdouble bx,
                                gdouble by,
                                gdouble length);

Calculates force as evaluated from z-component of the magnetic field for a given probe type.

Parameters

hz	Data field contaning the Z-component of the magnetic H field.
fz	Target data field to put the result to. It will be resized to match hz .
type	Probe type.
mtip	Probe magnetic moment.
bx	x size for parallelpiped probe.
by	y size for parallelpiped probe.
length	length (z size) for parallelpiped probe.

Since: 2.51

gwy_data_field_mfm_shift_z ()

void
gwy_data_field_mfm_shift_z (GwyDataField *dfield,
                            GwyDataField *out,
                            gdouble zdiff);

Shifts magnetic field to a different lift height above the surface.

Positive zdiff means away from the measured surface and blurring the data. Negative zdiff means shifting towards (or within) the measured surface and sharpening the data. For negative zdiff the result grows exponentially and is generally not very useful.

Parameters

dfield	Data field containing magnetic field component.
out	Target data field to put the result to.
zdiff	The shift distance in physical units.

Since: 2.51

gwy_data_field_mfm_find_shift_z ()

gdouble
gwy_data_field_mfm_find_shift_z (GwyDataField *dfield,
                                 GwyDataField *shifted,
                                 gdouble zdiffmin,
                                 gdouble zdiffmax);

Estimates the height difference between two magnetic field images.

See gwy_data_field_mfm_shift_z() for the sign convention. It is generally only meaningful to estimate the shift whe shifted was measured at larger lift height than dfield .

Parameters

dfield	Data field containing magnetic field component.
shifted	Data field containing magnetic field component measured at a different lift height.
zdiffmin	Start of shift scan range.
zdiffmax	Start of shift scan range.

Returns

The estimated shift between shifted and dfield .

Since: 2.51

gwy_data_field_mfm_parallel_medium ()

void
gwy_data_field_mfm_parallel_medium (GwyDataField *hfield,
                                    gdouble height,
                                    gdouble size_a,
                                    gdouble size_b,
                                    gdouble size_c,
                                    gdouble magnetisation,
                                    gdouble thickness,
                                    GwyMFMComponentType component);

Calculates magnetic field or its derivatives above a simple medium consisting of stripes of left and right direction magnetisation. Results are added to the hfield array, so it should be cleared if function is run only once.

Parameters

hfield	Resulting array.
height	Height above surface.
size_a	Left direction oriented area width.
size_b	Right direction orientated area width.
size_c	Gap size.
magnetisation	Remanent magnetisation.
thickness	Film thickness.
component	Component to output.

Since: 2.51

gwy_data_field_mfm_current_line ()

void
gwy_data_field_mfm_current_line (GwyDataField *hfield,
                                 gdouble height,
                                 gdouble width,
                                 gdouble position,
                                 gdouble current,
                                 GwyMFMComponentType component);

Calculates magnetic field or its derivatives above a flat current line (stripe). Results are added to the hfield array, so it should be cleared if function is run only once.

Parameters

hfield	Resulting array.
height	Height above surface.
width	Current line width.
position	Current line x position in the resulting array.
current	Curent passing through the line.
component	Component to output.

Since: 2.51

Types and Values

enum GwyMFMProbeType

Type of probe for calculation of force in magnetic field microscopy.

Members

GWY_MFM_PROBE_CHARGE	Magnetic point charge probe.
GWY_MFM_PROBE_BAR	Finite rectangular bar.

Since: 2.51

enum GwyMFMComponentType

Type of field component calculated in magnetic field microscopy.

Members

GWY_MFM_COMPONENT_HX	X-component of magnetic field H.
GWY_MFM_COMPONENT_HY	Y-component of magnetic field H.
GWY_MFM_COMPONENT_HZ	Z-component of magnetic field H.
GWY_MFM_COMPONENT_DHZ_DZ	Z-derivative of Z-component of magnetic field H.
GWY_MFM_COMPONENT_D2HZ_DZ2	Second Z-derivative of Z-component of magnetic field H.

Since: 2.51

enum GwyMFMGradientType

Members

GWY_MFM_GRADIENT_FORCE
GWY_MFM_GRADIENT_MFM
GWY_MFM_GRADIENT_MFM_AREA