High Coercivity High Resolution Magnetic Probes MFM_HC.

High Coercivity Magnetic Probes

Magnetic measurement in high external magnetic fields demands corresponding coercitivity value of MFM tip and stability of its magnetization distribution during imaging. Obviously, applying magnetic field higher than coercitivity leads to unavoidable magnetization reversal of magnetic tip and corresponding distortion of magnetic image.

Typical magnetic tips with CoCr coating usually demonstrate coercivity about 200Oe in vertical Z direction (see figure) and 800Oe in horizontal X or Y direction.

Novel magnetic tips based on Co high coercivity alloy (MFM_HC) posses essentially higher values – 500-800Oe in vertical direction and more than 2kOe in horizontal direction. Therefore new MFM_HC tips open new possibilities in magnetic measurements in high external magnetic fields.

 

Probe specification


Standard chip size: 1.6x3.4x0.3 mm compatible with the most of commercial AFM devices.
The base silicon is highly doped to avoid electrostatic charges.
High reflective Al back side coating.
Tip side is coated with Co-based high coercitivity alloy with additional layers protecting from oxidation.
Total coating thickness – 50 nm.
Typical curvature radius of the tip is about 40 nm.
Guaranteed cantilever lifetime is 6 months if it’s storaged at the normal conditions (humidity 30-40%).

Before the first use prior magnetization of the tip along its axis (Z direction) in a strong magnet (more than 1kOe) is recommended. It helps to improve magnetic signal in 1,5 times. Coercivity of the probes remains the same.

 

Cantilever series
Cantilever length, L±10 µm
Cantilever width, W±5 µm
Cantilever thickness,
T±0.5 µm
Resonant frequency, kHz
Force constant, N/m
min
typical
max
min
typical
max
MFM_HC
225
32
2.5
47
70
90
1
3
5