Mannan Ali
Research Scientist
-
Research Interests:
-
Research Of Magnetostrictive Ferromagnetic Amorphous Films.- (METGLAS® 2605SC)
-
Recent studies include:
-
Assessing the influences of deposition parameters on the magnetic properties of magnetostrictive FeSiBC amorphous
films based on the METGLAS® 2605SC
composition; the films have been produced by RF magnetron sputtering. The ribbon form of the
material has excellent magnetic properties, which are ideal for magnetic thin film sensors. The deposition of
films is a complex process which is strongly dependent upon many parameters; these have been discussed and investigated
in detail.
Films have been deposited onto commercially important substrates such as GaAs, Si and
Si3N4,
which are compatible with the microelectronic fabrication technologies. This allows present and
future design of sophisticated devices where both the magnetic sensor and its electronic detection system are
fabricated on the one substrate, making it commercially more attractive.
It also eliminates the problem of bonding the magnetostrictive material to the fabricated device.
-
Construction of a Magneto Optical Kerr Effect (MOKE) magnetometer for obtaining point magnetic information from
thin films and fabricated devices.
-
Construction of a MOKE imaging system to compliment the above hysteresis measurements with domain structures-
( a special thanks to Dr R.Watts for writing the software. )
-
Investigation of the growth induced magnetic anisotropy in amorphous FeSiBC films - an unusual reproducible radial domain
structure was found to exist in magnetron RF sputtered films under certain conditions.
-
A high degree of control is demonstrated in tailoring the anisotropy field, using the technique of stress annealing.
The treatments are evaluated for their potential to enable the magnetic anisotropy in magnetostrictive device applications
to be controlled.
-
A simple new technique is developed for the measurement of saturation magnetostriction in thin films deposited
onto rigid substrates. The method is based on mechanically introducing a small curvature into the substrate. The
strain induced anisotropy is measured using the magneto-optical Kerr effect. Quantification of the film strain
is obtained using optical interference and stylus measurements; this allows the saturation magnetostriction to be
determined. No information about the mechanical properties of the substrate is required and, providing that the
Young’s modulus of the film is known accurately, the values of magnetostriction obtained are accurate and absolute.
It is envisaged that the technique could be applied to a wide variety of films deposited onto commercially important
substrates.
-
The effects of photolithography and miniaturisation of thin films - magnetic properties.
-
Magneto impedance measurements in FeSiBC films - collaboration with Instituto de Magnetismo Aplicado (Madrid - Spain)
-
Invited to the Dept. of Chemical-Physics of the University of the Basque Country (Bilbao, Spain), to
Construct a similar MOKE magnetometer system. -
( may I thank Prof. Fernando Castano (senior) for the invitation )
