Origin of the negative magneto-resistance in carbons and its relation with the degree of graphitization

In this study, flame-formed carbon nanoparticles of different nanostructures have been produced by changing the flame temperature. Raman spectroscopy has been used for the characterization of the carbon nanoparticles, while the particle size has been obtained by online measurements made by electrical mobility analysis. The results show that, in agreement with recent literature data, a large variety of carbon nanoparticles, with a different degree of graphitization, can be produced by changing the flame temperature. This methodology allows for the synthesis of very small carbon nanoparticles with a size of about 3-4 nm and with different graphitic orders. Under the perspective of the material synthesis process, the variable-temperature flame-synthesis of carbon nanoparticles appears as an attractive procedure for a cost-effective and easily scalable production of highly tunable carbon nanoparticles.

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Magneto resistance based perpendicular polarizer spin torque nano oscillator for the tuning of output power

10.1063/5.0016744 ◽

2020 ◽

Author(s):

Bhoomeeswaran H. ◽

Vivek T. ◽

Sabareesan P.

Keyword(s):

Output Power ◽

Spin Torque ◽

Magneto Resistance

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Influence of Magnetoelastic Anisotropy on Properties of Nanostructured Microwires

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.646.59 ◽

2013 ◽

Vol 646 ◽

pp. 59-66 ◽

Cited By ~ 1

Author(s):

Arcady Zhukov ◽

Margarita Churyukanova ◽

Lorena Gonzalez-Legarreta ◽

Ahmed Talaat ◽

Valentina Zhukova ◽

...

Keyword(s):

Heat Capacity ◽

Hysteresis Loops ◽

Magnetic Behaviour ◽

Soft Magnetic ◽

Magnetoelastic Anisotropy ◽

Thermal Expansion Coefficients ◽

Magnetoelastic Energy ◽

Expansion Coefficients ◽

The Difference ◽

Magneto Resistance

We studied the effect ofthe magnetoelastic ansitropy on properties of nanostructured glass-coated microwires with soft magnetic behaviour (Finemet-type microwires of Fe70.8Cu1Nb3.1Si14.5B10.6, Fe71.8Cu1Nb3.1Si15B9.1 and Fe73.8Cu1Nb3.1Si13B9.1 compositions) and with granular structure (Cu based Co-Cu microwires). The magnetoelastic energy originated from the difference in thermal expansion coefficients of the glass and metallic alloy during the microwires fabrication, affected the hysteresis loops, coercivity and heat capacity of Finemet-type microwires. Hysteresis loops of all as-prepared microwires showed rectangular shape, typical for Fe-rich microwires. As expected, coercivity, HC, of as-prepared microwires increases with decreasing of the ratio ρ defined as the ratio between the metallic nucleus diameter, d to total microwire diameter, D. On the other hand we observed change of heat capacity in microwires with different ratio ρ. In the case of Co-Cu microwires ρ- ratio affected the structure and the giant magneto-resistance of obtained microwires.

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Sputter Deposition of Fe-Co Nitride for Ferromagnetic Granular Nitride Thin Film

Materials Science Forum ◽

10.4028/www.scientific.net/msf.631-632.327 ◽

2009 ◽

Vol 631-632 ◽

pp. 327-331 ◽

Cited By ~ 1

Author(s):

K. Sakon ◽

Y. Hirokawa ◽

Yasuji Masubuchi ◽

Shinichi Kikkawa

Keyword(s):

Thin Film ◽

Solid Solution ◽

Thermal Decomposition ◽

Sputter Deposition ◽

Composite Target ◽

Zinc Blende ◽

Alloy Particles ◽

Sputter Deposited ◽

Magneto Resistance ◽

Zinc Blende Structure

Sputter deposited Fe0.7Co0.3 nitride thin film had zinc blende structure. It was thermally decomposed completely back to the ferromagnetic Fe0.7Co0.3 alloy above 400°C. As-deposited nitride thin films obtained in cosputtering of (Fe0.7Co0.3)1-xAlx composite target with nitrogen sputter gas were solid solutions with zinc blende (x≤0.44) and wurtzite (x>0.5) type structure, respectively. The largest magneto resistance ratio of 0.24% was observed on the Fe0.7Co0.3 alloy particles dispersed in AlN thin film obtained by thermal decomposition of the nitride solid solution with x=0.66 at 500°C.

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