Nanotechnology to improve hard disk quality (Iran)

[R_E_Z_A]

Nano Memories to Improve Magnetic Hard Disks' Quality
TEHRAN (FNA)- Iranian researchers managed to fabricate nano magnetic memories by means of hard magnetic alloy materials which could result in improvement of magnetic hard disks quality.

Magnetic nanoparticles provide local and independent magnetic behavior in a two dimensional space under a variable field.

The advantage of these spaces over multilayered ones is the single size of nanoparticles and removal of exchange interaction between them. This feature leads to stability increase of particles.

The capacity increase is caused by nanometric size of particles. The problem associated with this situation is the subjection of material to ultra paramagnetic phase in which instable nanoparticles magnetic orientation are formed after field is cut off. To overcome this limitation we need a strong magnetic anisotropy.

"The Production of magnetic nanoparticles through chemical synthesis and increasing their magnetic hardness by thermal treatment may bring about large coercivity in FePt nanoparticles after thermal treatment and create strong magnetocrystalline anisotropy," Majid Farahmandjou, one of the researchers told the news service of INIC.

As the first step, he dissolved FeCl2.4H2O, Pt (ac AC2, and hexadecanediol reductant in phenyl ether solvent at nitrogenic atmosphere. Then, he added oleic acid and oleylamine to the solution and heated it up to 200oC. At this temperature, a strong reductant called super hydride was added to the solution which resulted in fast release of metal atoms. After that, sample was purified in four steps.

Finally, sample was left in a furnace containing Ar and H2 together with NaCl salt at 600oC for a definite time. The result was a crystalline phase transition and magnetic coercivity enlargement.

The results of the present study show that stable FePt nanoparticles form after being heated at 700oC in salt separation medium through ultrasonic process.


http://english.farsnews.net/newstext.php?nn=8809120491
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[R_E_Z_A]

Iranian Scientists Find New Method for Production of Nanocomposites
TEHRAN (FNA)- The researchers at Ferdowsi University of Mashhad, Iran, introduced a new method for direct synthesis of nanocomposites from metallic oxides.

Mechanochemical synthesis based on materials production using chemical reactions is one of the mechanical alloying applications done by the energy resulted from milling which reveals an appropriate method for the synthesis of different nanocomposites and organic, inorganic, oxides and intermetallic compounds.

"The main purpose of the present study was to prove the possibility of activation of endothermic carbothermic reduction reaction of metallic oxides in the presence of exothermic aluminothermic reduction reaction and consequent production of nanostructured brass-alumina," M.A. Mara'shi, one of the Iranian scientists explained to the news service of INIC.

"In this research, the effect of aluminothermic reduction reactions on facilitating and accelerating carbothermic reduction reactions for the production of nanostructured brass-alumina by mechanochemical method has been investigated," she added.

For this purpose, she and her colleagues utilized carbon and aluminum elements as copper and zinc oxides reductive agents. Then they drew adiabatic temperature changes of overall reduction reaction versus initial amounts of aluminum and carbon by thermodynamic calculations. Four adiabatic temperatures of 298, 1300, 1800, and 2300 K were chosen for milling tests.

The milled specimens were undergone XRD tests at different times. TEM images were also applied to check if the resulting composites were nanostructured.

Tests results implied that reactions activate spontaneously in the case of compounds having adiabatic temperature equal to or greater than 1800 K and carbothermic reduction occured simultaneously with aluminothermic reduction so that brass-alumina nanostructured composite were synthesized after three hours of milling.

http://english.farsnews.com/newstext.php?nn=8809221931

 

[General Parsaian]

متشکر جناب رضا
حداقل باز اینجا یکی دو تا خبر خوش هم از ولایت شنیدیم

 

[Jahel]

If true, then good on Iranian scientists who, despite all kind of limitations by the IR (tight research funds, etc), as well as external sanctions, still keep on producing good research. I am IMPRESSED by the ingenuity of the PG students who come overseas for higher education particularly from the top 5-6 universities; they are simply UNBELIEVABLE and nothing surpriises me when it comes to such innovations.

Saying all that, and the fact that Iranian scientists do not have much active presence in top research and academic circles of the world (e.g., sanctions by the IEEE which may have been lifted by now, am not sure) makes the works done in Iran almost unchecked by the world standards. The IR research policies are also supportive of any ideas that relate to warfare and army. I just hope that IF this is a genuine breakthrough work, the researchers receive their fair share of their work by commercialising it in best possible ways rather than in 3 years time seeing that Hashemi Rafsanjanee's daughter owns an innovative CD manufacturing company in Merylands with undisclosed annual profits, as happened in the past.