Magnetic nanowire arrays and their temperature stability - Dissertation Example

? Address Current status Tel No Email DOB Career Objective To gain fluency and perfection in all the elements of physics and to have a prosperous research career after pursuing Ph. D in Physics. Qualification M.Sc. in Material Physics (pursuing) B.Sc. in Physics from Qassim University completed in 2008 Academic Experience and Project Awarded by the certificate for securing highest marks in Dept. of Physics for 2 consecutive years Submitted a well-researched Final Year Project on BIG-BANG Theory Work Experience Teaching experience in “fundamentals of physics” to the High school and Secondary school students Personal Experience/Interest Interest and Activities Has a keen interest in understanding and practicing different aspects of physics. Has been a part of college’s top students for continuously 3 years. Personal Details Work Schedule:- The following research proposal has been arranged in the below mentioned sequence. 1. Abstract :- A simple idea about the proposal and its significance 2. Background:- Identification, definition and justification of Magnetic Nanowire arrays. 3. Goals and Objectives: - As clear from the topic, this section includes the properties of nanowire arrays. 4. Research questions and hypothesis:- the main section of this proposal. Mostly deals with thermodynamic field and defines about the thermal properties of nanowire arrays. 5. Analysis plan: - Again a section on the magnetic properties and behavior of nanowire arrays. 6. Conclusion Magnetic nanowire arrays and their temperature stability Abstract: - This below proposal contains a report which is a research cum proposal on the Anodic Nanowire Arrays. These arrays have a high thermal stability and hence are used in so many applications as of today’s time. Use of these arrays have increased during last few years and now these are being used on a large scales in laboratories as well as other scientific institutions. Background:- Magnetic nanowires, fabricated by various methods, represent an important family of magnetic Nano structures. We focus on a particular category of magnetic nanowires: arrays of Nano wires prepared by electro-deposition into self-assembled pores in alumina. These nanowires are hexagonally arranged and highly ordered with wire to wire distances between 30 to 100 nm, wire diameters of 5 to 250 nm and lengths up to several ?m depending on the preparation conditions. Fig:- Hexagonally arranged Nanowire Arrays Ferromagnetic nanowires with diameters in the range of domain wall widths or even smaller are expected to behave as single domain particles. In the easiest case such nanowires can be interpreted as defect-free long ellipsoids with homogeneous magnetization and these represent model systems for the investigation of magnetic interactions because their magnetic properties are not obscured by difficult-to-control bulk domains. Within such nanowires the shape anisotropy, the magneto-crystalline anisotropy and – in the case of very fine nanowires (diameters about 5 nm) – the influence of the surface magnetism has to be considered. Depending on the distance between the nanowires the wires can be interpreted as magnetically isolated magnetic mono-domains or, in the case of arrays in alumina, as dipolar interacting mono-domains. For the understanding of the behavior of such arrays both theoretical and experimental investigations are essential. In the following we will just present experimental results which demonstrate the basic magnetic properties. Hysteresis loops of arrays of Co-nanowires in alumina with different diameters and roughly the same length with H parallel (II) and perpendicular (^) to the long wire axis. Aside from the scientific attitude such arrays of ferromagnetic nanostructures are of significant interest because of their possible application as ultrahigh-density magnetic recording media. The preparation of such systems is very cheap and fast compared to expensive and time consuming methods as microlithography and molecular beam epitaxy. In addition the diameter, interwire distances and the lengths of the wires and therefore the magnetic properties of the system can easily be controlled by varying the electrochemical parameters such as electrolyte, voltage and temperature. Goals and Objectives:- In the following the magnetic properties of homogeneous nanowire arrays of Fe, Co, Ni and its alloys in alumina are introduced. In general the shape anisotropy of the wires and the dipolar interactions among the wires dominate the magnetic behavior. According to the model there should be no hysteresis if the external field is applied perpendicular to the long axis. This behavior indicates two stable orientations of the magnetic moments, namely pointing parallel and anti-parallel to the long axis of the wire. The hysteresis curves for the parallel measurement are slightly sheared. This can be attributed to dipolar interactions between the wires. The slight hysteresis that can be seen for the perpendicular measurement is probably due to a slight misalignment of the wires and due to the influence of the rather weak magneto crystalline anisotropy. According to the model for a long magnetic cylinder increasing the length of the nanowires increases the shape anisotropy and decreasing the diameter also increases the shape anisotropy. Research questions and hypothesis:- One significant challenge in Nano manufacturing is the development of simple techniques to deposit or grow Nano materials uniformly across large regions, while simultaneously controlling the spacing and arrangement of the individual particles or structures.  While self-assembly techniques can be used to deposit colloidal Nano materials from solution to form ordered superlattice films, it is challenging to use such methods to create non-periodic arrays or films that are not close-packed.  ZnO is a wide-bandgap semiconductor with potential use in photovoltaic, optoelectronic and piezoelectric applications.  While high-quality zinc oxide nanostructures with an astounding variety of morphologies have been grown in the past, these methods have often used synthetic conditions – such as high temperatures (> 500 °C) or metal catalyst particles – which are incompatible with other processing steps used for device fabrication.  Significantly, the procedure presented by Xu and co-workers uses relatively low temperatures ( Read More