the Bloch wall

[pinestone]

Hi all

I've moved this discussion from another thread. We were talking about the Bloch wall, and the null zone of magnetism.
This is where north twists into south and is an elusive topic, to say the least.
There's not much information out there on this subject, but I'd like to discuss it anyway.

A while back, I placed two little neos on the surface of one of my lenses and produced this image.

Additionally, I used a modified computer monitor that has a Sony Trinitron CRT. Placing a 1 Tesla magnet (yellow shrink tubing around it) on the screen produced the other (larger) image.

I think both are representing the lowest potential of the magnetic flux, and both reveal the Bloch wall.

Comments?

[Onevoice]

Sorry, I don't have constructive comments. Not sure I understand the 1st picture. Can you please explain more about what and how it represents and on the 2nd picture. Can you please point out the north & south poles. Are they top-down or left-right?

[pinestone]

Sorry, I don't have constructive comments. Not sure I understand the 1st picture. Can you please explain more about what and how it represents and on the 2nd picture. Can you please point out the north & south poles. Are they top-down or left-right?

You can read about the lens here: http://www.nanomagnetics.us/

The magnetic orientation is N and S on the ends of the magnets in both images.
These are the separate images that I combined in Photoshop to create this:

[Onevoice]

Is there any kind of scale for the colors. Are they just alternating bands or does the color imply a certain flux density?

Its interesting that the envalopes of the fields look like they're almost perfect 45deg angles. What shape is the magnet you're using?

[pinestone]

Is there any kind of scale for the colors. Are they just alternating bands or does the color imply a certain flux density?

Each color on the crt image represent a different phase of the magnetic field. Blue is neutral, violet is north and yellow is south.
I'm not sure why there are multiple bands of colors (instead of one set), but it must have something to do with the induced field into the microgrid of the crt. I haven't thought too deeply about it. Maybe someone else reading these posts can offer an explaination.

The reason these colors are not the typical ones (red, blue and green) is that the crt I used for these tests has one defective gun.
I modified an old computer monitor by applying a small dc voltage to the video inputs (which turn on the video circuits), but sometime during my testing, i managed to destroy 'green'. The fact that we still get three different colors is what convinced me we are seeing the phase shift of the magnetic field. I have more pix using a different monitor in which all three guns work properly- I'll post a couple of them when I get back to the lab on Monday.

Its interesting that the envalopes of the fields look like they're almost perfect 45deg angles. What shape is the magnet you're using?

These two images were taken using cylinder magnets. But regardless of the type of magnet used, the resulting images are the same.
What's not apparent in this image, is the crt image is two dimensional whereas the Flux Resonator image is three dimensional in real life. One of my collaborators is setting up a new experiment utilizing two cameras so the resulting images appear as 3-D. I'll post a link to his work when he makes them available.