Spintronics is based on manipulating the flow of spin polarized current in metals and semiconductors. Introducing spin degrees of freedom and charge into the present semiconductor electronics at nanoscale level is a very important issue for realizing novel devices. Research is being carried out for the development of magnetic random access memories and nonvolatile logic applications by extensively studying novel spin based semiconductor device structures and magnetic material semiconductor hybrid structures. We can create spin polarization using many methods, that will lead to hole induced ferromagnetism in the case of InAs and GaAs alloyed with Mn [1]. This made it possible to integrate ferromagnetism with existing nonmagnetic Ill-V heterostructures. Carrier concentration has been modulated using insulating gate field-effect transistor structure and we were able to realize reversible electrical switching of the ferromagnetic phase transition and coercive force [1]. Ferromagnetic semiconductors may prove to be useful in developing spintronic devices that combine magnetization switching with other spin-related effects, once the transition temperature of these materials reaches well beyond room temperature. An overview of semiconductor spintronics has been presented here:
• GaMnAs based heterostructures: It was observed that highly coherent tunneling occurs in Gallium Manganese Arsenide(GaMnAs) based heterostructures, when the GaMnAs quantum-well thickness was varied from 3.8 to 20 nm. To observe resonant tunneling in this system, it was found that the Fermi level of the electrode injecting carriers is important [2].
Materials drawing a lot of attention for spintronic applications are dilute magnetic semiconductors (normal semic...
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...compared to moving the electrons.This polymer-based magnet semiconductor has been applied as a spin polarizer (to save data) and a spin detector (to read the data). It is flexible, light weight, low cost, easier to fabricate. Curie temperature is above 350K [4].
• Researchers at North Carolina State University have fabricated a new compound, Strontium tin oxide (Sr3SnO). Sr3SnO is a dilute magnetic semiconductor, which can be integrated into silicon chips. Researchers could not effectively integrate the other dilute magnetic semiconductors materials on a silicon substrate. This is needed so that they can be used in smart devices. The researchers synthesized Strontium tin oxide (Sr3SnO), as an epitaxial thin film on a silicon chip. Transistors operating at room temperature based on magnetic fields instead of electrical currents could be developed using Sr3SnO [5].
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The electronics industry relies heavily on devices that acquire, store and transmit data. NVE Corp’s spintronics technology focuses on magnetic sensors, couplers, and memory which perform these activities w...
Gadolinium and its performance were limited by the use of passive regenerators and heat exchangers in the refrigeration cycle [25]. So, a magnetic refrigeration device must utilize a regenerative process to produce a large enough temperature span to be useful for refrigeration purposes [26].
One reason Kealing Magnet Program would be a good fit for me is because I am a hard-working student who wants to get ahead and learn a lot. Another reason is because I want a challenging school, and Kealing Magnet is challenging, but also very helpful. I define a challenging school as a school with a lot of work. I want to apply to the McCallum Fine Arts Program for high school, and going to Kealing would give me knowledge and support in that. Being at Kealing would be a fun and accommodating opportunity, while also educating me. I want to both enjoy school and learn things, and Kealing would satisfy that for me. I have looked at the website and am looking forward to the piano in the choir in particular. I have been having piano lessons for about two years now, and that sounds like a fun activity for me.
I define a hard worker as someone who is willing to struggle and work hard, despite the fact that nobody will notice. Inside this essay, I will explain not only how I match this description, but also exactly how the Kealing Magnet Program is the optimal place for me to meet my goals, and how I will contribute to the community in ways outside of academics. Although my current school, Austin Home Base, has been great, I am ready for something new, and challenging.
Figure 1 shows the temperature dependence of magnetization in Gd5Si2Ge2 compound at and at atmospheric pressure. Open symbols are the experimental data and the solid symbols represent the theoretical curve. The circles are for sample heating and triangles are for sample cooling. The value of saturation magnetization at 8 K in the theoretical curve was normalized with the experimental data. The values of and were adjusted according to the critical temperatures from the M vs. T curves (Fig. 1) at atmospheric pressure for sample heating and cooling (table 1). It is worth noticing that fixes the Curie temperature and is responsible for the existence of first order magnetic phase transition and fixes the thermal hysteresis of about 5 K.
Magnets are one of the fundamental items in physics. This page is designed in order to provide a general overview of magnets and their uses as well as an in depth look into certain aspects of magnetism.
Do you know why people bann fidget spinners in school or do you know why people don’t allow kids to own fidget spinners. I am against fidget spinners because many parents well ones that are wusses and some kids but i’m against them because kids get hurt but then once the kids get hurt they learn and won’t do it again but also it’s a distraction and also they can hurt somebody severely if used improperly and it’s a 50% chance to severely hurt somebody. If you don’t know what is a fidget spinner well a fidget spinners are a little handheld object about 2 inches long and they weigh about 2 pounds as well. The people who buy fidget spinners for themselves are probably around the ages of 5-18. The reason fidget spinners were made is that it was supposed to help kids with paying attention. The reason why parents or adults hate the fidget spinners is because the toy that is used for paying attention ends up becoming a distraction. The main thing that is going on with fidget spinners is that they are
such as Sr, Ba, and Pb or a mixture of these [12]. Barium hexaferrites (BaFe12O19) with a magnetoplumbite structure are well known as hard magnetic materials which are based on iron oxides. Hexagonal ferrites are referred to as hard because the direction of magnetization cannot be changed easily to another axis [].Barium ferrite possesses relatively high Curie temperature,
Magnetic materials are categorised as either hard or soft. A soft magnet material is easy to magnetise/demagnetise, whereas hard magnetic materials retain their magnetic properties after being magnetised. Permanent magnets are made up of hard magnetic materials which is able to create its own persistent magnetic field once magnetised. They can be made in different sizes and strength and thus, making them implantable into the body without anatomical restriction.
Using the d-orbital electron configuration for cobalt in high and low states, the number of unpaired in electrons can be used to calculate the magnet moment for each spin state using the equation, µso¬ = √(4S(S+1)), where S = ½ the number of unpaired electrons. The magnetic moment for the high spin state was calculated to be 8.944 and 0 for the low spin state.
Perm-alloy is usually used material for magneto-resistive sensors because of mainly two reasons. First is due to its high magneto-resistive coefficient. Secondly its characteristics are suitable with the fabrication techniques which help to make silicon integrated circuits. Perm-alloy consists of 20%Fe and 80%Ni. Fig.7 shows typical magneto-resistive curve for perm-alloy. Resistance will change only 2% under saturation condition [11-15].
Humans these days take electricity for granted. We don’t truly understand what life was like without it. Most young adults will tell you their life does not depend on electricity, but they aren’t fooling anyone. They all know that their life depends on electricity; whether it’s television, their phone, Google, or the lights in their house. We need to stop taking those things for granted and give credit where credit is due. That is why I chose to write about the scientists who contributed to the discovery of electricity, which then helped modern scientists fuel the electricity phenomenons we now have today.
Grundmann, Marius. Physics of Semiconductors: An Introduction Including Devices and Nanophysics. New York: Springer, 2006. Print.
Temperature has a large effect on particles. Heat makes particles energized causing them to spread out and bounce around. Inversely the cold causes particles to clump together and become denser. These changes greatly F magnetic the state of substances and can also influence the strength of magnetic fields. This is because it can alter the flow of electrons through the magnet.
Semi-hard magnets can be regarded as a special category of permanent magnets which are used for analog and digital magnetic recording.