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Using the Multi-Mode Scanning Probe Microscope (MM SPM)

Magnetic Force Microscopy

This manual describes the steps of everyday use of the SPM, specifically in its capacityas a Magnetic Force Microscope (MFM) in TappingMode. This is meant to be read andused after working and becoming comfortable with the microscope in TappingMode, and

it can be used in conjunction with the manual specifically addressing that mode of usage.

Two topics are covered that must be handled slightly differently than in TappingMode:

1. Setting up for Microscope Usage. Pg 2

2. Taking an Image Pg 3

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Setting up for Microscope Usage

1.1 Turn on the Equipment

Turn on the computer, access the program Nanoscope v4.43r8, and turn

on the microscope.

1.2 Place the Sample in the Microscope

Remove the tipholder from the head and, using the Scienscope stereoscope,

make sure that the correct tip is in the tipholder. The MFM tip is shinier than

the TM tip, and it has writing (NANOSENSOR) on it. (By now you shouldhave learned how to change the tip, but if not, learn now.)

The MFM tips are located in the Dry Keeper in a plastic case (containingblack foam) that is labeled Magnetic Force Microscopy Probes, Magnetizer,

and Sample.

Magnetize the tip by placing the magnetizer (which can be found in the

Multimode Magnet Holder) and the tipholder together so that the circularregion of the magnetizer is in the region under the tip where the samples go.

Put the sample on the magnetic stage and return the tipholder to the head of

the microscope as usual. (A generic sample that is good to practice scanningis also in the case with the MFM tips.)

1.3 Adjust the Microscope (see SPMI Ch. 8; 8.3.2)

Adjust the probe, laser beam, mirror, and photodetector just as you would

for normal usage of the microscope in TappingMode. The only difference isthat when the tilt mirror lever is adjusted so that the signal sum display reads a

maximum signal, the maximum is a little over the 6.0 V level (rather than near3.6 V).

1.4 Tune the Cantilever (see SPMI Ch. 13; 13.2)

Look at the bottom of the Nanoscope Control window and make sure that

Tapping AFM is written to the right of Extended Multimode. If it isntwritten (perhaps Contact AFM is there instead), then click on Microscope

at the top of the Nanoscope Control window and select Profile. Select !

Tapping AFM and click on Load.

Look in the Other Controls sub-window to make sure that the Microscopemode is set to Tapping.

Click on the tuning icon to access the cantilever tuning controls.

In the Cantilever Tune sub-window set the following parameters to theirassociated values, if they are not already:

o Start frequency: 50 kHz

o End frequency: 100 kHz

o Target amplitude: 2 V

o Peak offset: 0 %

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Complete the tuning process. (The drive frequency should be 69 91 kHz.)

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2. Taking an Image

2.1 Enter the Initial Settings (see SPMI Ch. 13; 13.2.1)

Enter the initial settings as you would for normal tapping mode, except for the

following settings: Interleave Controls sub-window

o Make sure that Input feedback, Drive frequency, Drive phase,

and Drive amplitude are set to the main controls values by settingthe bullets to off or gray, rather than green. (In regular tapping

mode, the bullets are also gray.)

o Interleave mode: Disabled should be selected, for now.

o Lift start height: 0 nm

o Lift scan height: 100 nm

Channel 1 sub-window

o Data type: Height should be selected.

o Line direction: Retrace should be selected.

o Scan line: Main should be selected.

o Realtime planefit: Line should be selected.

o Offline planefit: None should be selected.

Channel 2 sub-window

o Data type: Phase should be selected.

o Data scale: The value should be 3.

o Line direction: Retrace should be selected.

o Realtime planefit: Line should be selected.

o Offline planefit: None should be selected.

2.2 Engage

Look at the base of the microscope and check that the light is green and the

lower display reads a vertical difference between 1.00 V and 1.00 V.

Engage. If an Engage sub-window appears that asks, Interleave mode is

enabled continue? then click on No and set Interleave mode to

Disabled in the Interleave Controls sub-window and re-engage.

Once engaged, change the Interleave mode to Lift and make sure Scanline in the Channel 2 sub-window is set to Interleave.

2.3 Adjust the Settings As usual, decrease the Channel 1 Data scale so features become clear, and

adjust the Channel 2 Data scale, when or if it needs adjusting.

The Amplitude setpoint should be set low enough to get a good plot of the

surface features, but set to the highest value possible. However, it shouldnt

be so high as to allow the magnetic field pattern to show up in the heightimage. (The less the tip is in contact with the surface, the more the magnetic

field will affect its path.)

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The integral and proportional gains will probably need to be adjusted as well.

2.3 Capture Images and Disengage

Use the same procedures as usual to capture images and disengage.

Dont forget to add notes to your images and to correct (modify, flatten) them.

And remember to clean up after yourself.

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