Change structure and structure of Nano Material (PhD in Nano _ Microelectronics)
Researcher and author: Dr. ( Afshin Rashid)
Note: All atoms in nanomaterials at any temperature have a certain amount of energy due to their fluctuations. The amplitude of this oscillation is not the same in all nanomaterial atoms. On the contrary, surface atoms have more amplitude of oscillation due to the greater freedom of space they have. In this way, the strange behavior of solids in reducing their melting temperature can be explained.
When the average amplitude of the atomic vibrations reaches a certain coefficient of the constant value of the nanomaterial lattice, these vibrations can no longer increase without damaging and destroying the nanoparticle lattice. Therefore, by increasing the average amplitude of vibrations to greater values, the material is removed from the crystal lattice mold and melted. Surface atoms have higher average oscillations, and if the number of surface atoms increases, they can have a clear effect on the average amplitude of the oscillations of all matter atoms. Therefore, with the reduction of the dimensions of the material to the extent that the ratio of the number of surface atoms to the number of volume atoms reaches a significant value, the average amplitude of nanomolecular oscillations will increase significantly; Under these conditions, as the surface instability of the material increases , the melting temperature of the nanomaterials will decrease.
In the transformation of nanomaterials from thermal phenomena due to shrinkage of material structure, is the thermal instability of nanoparticles. As you know, (heat has energy E), which - 03 - the amount of energy is proportional to the ambient temperature. This energy is equal to KBT. In this relation KB is the Boltermann constant and a constant value equal to and T is the temperature in Kelvin. Therefore, when materials are placed in different environments, energy is given to electrons (-0.01 * 0 / 33JK) due to heat. Now consider a property of a particle that generally depends on (nanoparticle volume V). The energy of this property is U and a function of V. When the volume is small enough that the KBT is larger than U, then the condition will be thermally unstable.
Conclusion :
All atoms in nanomaterials at any temperature have a certain amount of energy due to their fluctuations. The amplitude of this oscillation is not the same in all nanomaterial atoms. On the contrary, surface atoms have more amplitude of oscillation due to the greater freedom of space. In this way, the strange behavior of solids in reducing their melting temperature can be explained.
Researcher and author: Dr. ( Afshin Rashid)
PhD in Nano-Microelectronics