User:Andy Maloney/Notebook/Lab Notebook of Andy Maloney/2010/02/10/PBL1: Difference between revisions
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==Introduction== | ==Introduction== | ||
Since I will be dealing with magnetic iron nanoparticles, I need to explain what the terminology means for magnets. | Since I will be dealing with magnetic iron nanoparticles, I need to explain what the terminology means for magnets. | ||
===Diamagnetism=== | ===[http://en.wikipedia.org/wiki/Diamagnetism Diamagnetism]=== | ||
Some materials will actually deflect external magnetic fields such that they can exclude the external magnetic field from going through them. An example is the picture below. | Some materials will actually deflect external magnetic fields such that they can exclude the external magnetic field from going through them. An example is the picture below which show pyrolytic carbon, taken from Wikipedia's article on diamagnetism. | ||
< | http://upload.wikimedia.org/wikipedia/commons/c/c9/Diamagnetic_graphite_levitation.jpg | ||
<font color = red>Insert picture of field lines going through a material</font> | |||
Another cool image is this movie which shows a [http://www.hfml.ru.nl/pics/Movies/frog.mpg levitating frog]. | |||
Heuristically, diamagnetism comes from the material producing an opposing magnetic field that excludes the external magnetic field. | |||
===[http://en.wikipedia.org/wiki/Paramagnetism Paramagnetism]=== | |||
Paramagnetism is a weak effect of materials and can only be detected when an external magnetic field is applied. Paramagnets follow [http://en.wikipedia.org/wiki/Curie%27s_law Curie's law] (if the magnetization of the material is weak) which can be stated as: | |||
<center> | |||
<math> | |||
\boldsymbol{M} = \chi \cdot\boldsymbol{H}=C\cdot \frac{\boldsymbol{H}}{T} | |||
</math> | |||
</center> | |||
Or, more generally as: | |||
<center> | |||
The magnetization of a paramagnet depends linearly on the external magnetic field and inversely on the temperature. | |||
</center> | |||
Revision as of 08:53, 10 February 2010
Problem
In class, we were given a problem and an associated grade sheet. My portion of the presentation is Part B stated in the problem sheet. Below, I have outlined what I must talk about.
- Iron nanoparticles
- Properties
- Advantages for their use
- Disadvantages for their use
- Coatings
- Nobel metals
- Silica
- Oxides
- Polymers
- Discuss the above coatings and how:
- They prevent degradation from oxygen and H2O.
- The coatings affect the iron nanoparticle properties.
This is a problem based learning exercise that necessitates group activity. The members of my group are dealing with Part A outlined in the problem sheet where they have doled out the various parts of making a quantum dot for a specific biological investigation. Their components include: picking a target (one person), synthesis of the quantum dot (one person), and characterization of the quantum dot (one person). It looks like I got the short end of the stick here...
Introduction
Since I will be dealing with magnetic iron nanoparticles, I need to explain what the terminology means for magnets.
Diamagnetism
Some materials will actually deflect external magnetic fields such that they can exclude the external magnetic field from going through them. An example is the picture below which show pyrolytic carbon, taken from Wikipedia's article on diamagnetism.
http://upload.wikimedia.org/wikipedia/commons/c/c9/Diamagnetic_graphite_levitation.jpg
Insert picture of field lines going through a material
Another cool image is this movie which shows a levitating frog.
Heuristically, diamagnetism comes from the material producing an opposing magnetic field that excludes the external magnetic field.
Paramagnetism
Paramagnetism is a weak effect of materials and can only be detected when an external magnetic field is applied. Paramagnets follow Curie's law (if the magnetization of the material is weak) which can be stated as:
[math]\displaystyle{ \boldsymbol{M} = \chi \cdot\boldsymbol{H}=C\cdot \frac{\boldsymbol{H}}{T} }[/math]
Or, more generally as:
The magnetization of a paramagnet depends linearly on the external magnetic field and inversely on the temperature.
