Because of the themperature it seems to me that you can do it only in a hoven or in a furnace, if you do not have a programmable one you should change temperature directly acting on the temperature control trying to make it uniform (e.g. increasing it of 10°C every 3 minutes). If you need special atmosphere you should take in account. Finally is better if you text on a small quantity before.

You should try this heating with a programmable furnace. If it has a PID programmer, then you have to set a ramp rate (= ~96 minutes to reach the temperature 320oC) according to you desired heating rate.

The standard way is to use a temperature controlled heating mantle to heat a two neck round bottom with a condenser attached. One port of the two neck has the condenser attached, and the other is an injection port for adding reagents during the reaction, your thermocouple, and your input gas stream. However, a temperature controlled heating mantle can be very expensive, so less expensive methods are often used. A simple manually controlled heating mantel sized to your round bottom (or larger and filled with sand) can be used as long as you monitor the temperature. I would recommend mounting the heating mantel on a lab jack for easier fine tuning of your temperature. Also, in my experience, the heating rate is less important than having good control over the equilibrium temperature. Generally, how tightly controlled you are around the synthesis temperature dictates how monodispersed your particles are.

I agree with Tom. We also use a thermal decomposition method to synthesize SPIOs and we have used both programmable and manual heating mantles. From our experience the programmable one does not have as fine control as these protocols often detail, so we've found that the manual works fine. Evaporating as much moisture as possible before ramping up the temperature has also helped in synthesizing more monodisperse samples.

I agree with Jan, but instead of a heating mantle, you can get a temperature controler, directely conected on a heating plate, the only thing that you will need is a silicon oil bath to reach the temperature and set the increse on the heating plate.

Such kind of fine tuning needs to be implemented using programmable furnaces, otherwise the manual control could stem some sort of human errors.

I thank to all your kind answers. It should be a good experience to me in doing experiments, thermal decomposition. And I saw that you told about the programmable and manual heating mantle. So I can use a heater with "stirring, heating and timer" ., maximum 380 Celsi degree with small quantity. In addition, the problem is about Silicon oil bath. I checked that the temperature is around 200 Celsi degree for Silicon oil to works well. But I need 320...

yeah silicone oil baths wont work, I had trouble with this myself. As a few others have mentioned manual control of the ramp rate will yield good results. I ended up using a high temp, round bottom flask, heating mantle and just covered everything but the control in foil making sure that the heat convection was able to escape between the mantle shell and heating element (otherwise it will melt...trust me). If you are after particles below 20 nm make sure you have good control of the iron oleate and oleic acid ratio, its very important. As others have mentioned above, while ramping the temp up, hold it at 110 until all the moisture has escaped before you seal the reflux and take it higher. This will give much more monodisperse particles. I have just finished my thesis on applications of core shell magnetite by thermal decomp....have fun :)

Thanks Jos!! i'll try it ^ ^

I literally just had to hunt this reference down for another document and realised you may find it useful.

http://www.sciencedirect.com/science/article/pii/S0927775712003846#

"Influence of morphology and surface exchange reaction on magnetic properties of monodisperse magnetite nanoparticles"

yeah, that's nice ! I will get it for my work :) Thanks !

Have you ever thought to use A TGA furnace for heating up the material supposing that a crucible could contain enough of it for your purpose?

OK I didn't know about Schlenk line - I was assuming a TGA in N2 atmosphere using crucible with lid ... sorry my mistake

Jan: Yesss, I have one ^ ^ I am trying this, That I has just thought this afternoon ^ ^ paolo: no problem!

I am explaining my experience....I used to frequent use of 350 c for my synthesis using programmable heating mentle, shclenk line with N2 gas and vacuume manifold, three kneck flask....precursor (OLEATE BASED), oleic acid and solvent ration is an important factor. Temperature increasing rate 5c/min in my exp. Someone needs to care about the solvent boiling point....tri-n-octylamine, oleyamine, etc is high boiling point solvent (above 300)......it may help you..

I did the experiments, but not use vacuum manifold. And I also got the results, 4-8nm , dispersed in Chloroform. I may try with another solvent and your process later. Thank you a lot!! And thank all your answers! it helped me a lot! :)

A simple rotamantle you can use

Did you try this method? http://www.nature.com/nmat/journal/v3/n12/abs/nmat1251.html

Maybe you can try heating the Fe-Oleat Complex in a 1:1 Mixture of Oleic Acid and Oleylamine. Good luck.

Yeah, one of my advisors gave it to me, and I try ^_^ Thanks a lot :)

The oleic acid shoud react with Oleylamine and produce small amounts of water, this sounds during the reaction like a deep fryer. First time I used this procedure I wondered a little.

When you want to do core shell, what will be your core? Some Lanthanide ions also have a strong magnetic moment, not like iron oxide but maybe strong enough.

My goal is for Biomaterials. I did think about the other materials Co, Mn,... but I chose Fe (biocompatible) - I am firstly working with magnetic materials ^_^ Thanks for your ideas :)

 Dear Tom Morgan,

Can you suggest about a company which can provide good quality heating mantle with PID controller?

I have done my lab project on same topic. I prepared 0.5 degree per minute to 30 degree and observe a clear size different which was my gaol. I used normal heating mantle but manage it manually, but you can used power heating controller to control the temperature rate.