This is a practical and theoretical question about magnetic fields.
Here is my phone case
That circle in the middle is advertised as:
Inside the center of the finger holder ring there is a piece of hidden iron that allows the case to be attached to the magnetic car holder.
Here is the magnet
This is advertised as a NdFeB magnet 30mm by 10mm disc with strength N52.
I hope that placing the magnet next to the phone case on-axis will create the strongest attraction. And I am hoping that it will resist axial movement (remain on-axis but pull away) as well as lateral movement (remain touching disc-to-disc but moved off-axis).
The strongest attraction is made when the phone case is touching the magnet face-to-face with a planar offset of one radius from the center.
Placing the magnet face-to-face with the phone case directly on-axis produces zero attraction or repulsion. It is unstable because it would really rather be 1r in any direction. It's like balancing a pea on top of a soccer ball.
A video demonstrating this is at: https://youtu.be/b5RiXP5SVkQ
Why does this magnet attract in this way? Would a different magnet give my desired behavior?