NEW MATERIALS AND NANOTECHNOLOGY
SCANNING NON-FORCE MAGNETIC MICROSCOPE
Description
At development of new materials the check of their local
microscopic properties (magnetic, electric, structural) is
necessary. One of devices for study of local parameters of
materials is the scanning magnetic microscope (MM). In
ILTPE of NASU the experimental samples of scanning
non-force MM of three types are developed. Two of
them are intended for measurement of the parameters of
a local constant magnetic field on a surface of
investigated object (IO) (Fig.1), and third one are
intended for measurement of the local alternating IO
magnetic field (Fig.2). The novelty of the development is
protected by the Ukrainian patent. The sensitivity of the
MM detectors is in a range of 10-9 - 10 -12 Tesla at MM
spatial resolution of 1-10 microns for a permanent
magnetic field and of 10-50 microns for a alternating
field. The indicated MM are intended both for detection
and location of magnetic particles(Fig.3) and structural
defects on a surface and in depth of magnetic and nonmagnetic conductive materials (Fig.4).
The indicated functions can be incorporated in one
microscope. The operating principle of the indicated MM
allows to enhance the spatial resolution up to sub micron
range. In contrast to known analogs the proposed MM:
a) can be used for measurement of the constant and
alternating magnetic field;
b) includes measurements of magnetic and non-magnetic
objects having complex profile by method of eddy
currents;
c) does not require applying of deficient liquid helium for
a SQUID - detector, as it operates at Т = 77К
Fig.1 External view of magnetic microscope (MM)
1. Measuring channel with SQUID for "cold" objects study; 2.Measuring channel with fluxgate for "warm" objects study; 3.Measuring channel with SQUID for "warm" objects study; 4.Scanner driving device; 5.- SQUID and fluxgate electronic
amplifier; 6.- Personal computer
Fig.2. Appearance of the alternating magnetic field microscope, 1specimen holder, 2- fluxgate detector. 3-precesion moving table,
4- rough moving table
Innovative Aspect and Main Advantages:
Super high magnetic sensitivity
Possibility to operate using the same device
both at passive measurement regime of the local
permanent magnetic field of the object and
active regime by eddy current method for
nonmagnetic objects.
- Absence of the visible force and magnetic
effects on the testing object.
Usage of the proposed technology provides more
information for materials investigation at the non
destructive diagnostic of different units ( in field of
aviation, atomic industry, space industry, chemical
machinery
-
Areas of Application:
Offered MM can have application for a nondestructive evaluation in an aviation, atomic industry,
space industry, chemical machinery.
Fig.3. MM image of the vertical component of a magnetic
field over a small magnetic particle (the size is about 400 m)
Fig.4 Scan image of the magnetic field distribution over a hole of
a diameter 23mm in an aluminum-alloy plate of a thickness 25.4
mm; the frequency of the excitation magnetic field is 3 kHz
Stage of Development:
Prototype of the microscope available
Contact Details:
Institute for Low Temperature Physics and Engineering
of NASU
Bondarenko Stanislav Ivanovich
47,Lenin ave., Kharkov 61103, Ukraine
phone: 38-057-3308533
fax: 38-057-3402223
bondarenko@ilt.kharkov.ua