The public discussion took place for the Doctoral student (Anhar Abdul Salam Awda) at Anbar University, College of Science, Department of Physics, on Sunday 12/22/2024 in Ibn Sina Hall, for his tagged thesis

" Investigating Electric and Thermoelectric properties of some Endohedral Fullerenes compounds"

The discussion committee consisted of:

Prof. Dr. Ismat Ramzi Abdul Ghafour - Anbar University - College of Science - Chairman

Prof. Dr. Bahjat Bahlol Kazim - Al-Mustansiriya University - College of Science - Member

Prof. Dr. Zain Al-Abidin Yousef Mujbil - Al-Qasim Green University - College of Science - Member

Prof. Dr. Azmi Tawfiq Hussein - Anbar University - College of Computer Science and Information Technology - Member

Assist. Prof. Dr. Mazen Abdul Hamid Abdul Qader - Anbar University - College of Science - Member

Prof. Dr. Alaa Ahmed Dayeh - Anbar University - College of Science - Member and Supervisor 

 

A cage of fullerene C60 is utilized as a possible building block for molecular-scale electronic devices. Density Functional Theory (DFT) is implemented in the SIESTA package with non-equivalent Green's function has been applied to study the M@C60 molecular devices (where M = nLi, nNa, nK (n=1, 2, and 3), Sc, Co, Ni, P, As and Se) between two types of electrodes (gold and graphene).The electrical transmission coefficient T(E) is calculated by attaching the scattering region of (M@C60) to the gold and graphene electrodes. Gold and graphene demonstrate remarkable electrical conductivity which promotes efficient charge transfer in electronic devices. The electric Conductance (G), Seebeck S thermal conductance κ, and figure of merit ZT are also investigated. The result of the fullerene cage bound to gold electrodes is compared with the same fullerene bound to graphene electrodes. We found that the T(E) for the graphene electrodes is lower than the gold electrodes.  On the contrary, the S for graphene electrodes are higher than in the gold electrodes. In both gold and graphene electrodes, the results show an extra resonance are appears close to the fermi level EF=0 eV when doped by ions compared with bare structure (C60). These extra peaks are useful for tuning the electric conductance and Seebeck coefficient. Another powerful calculation is done by investigating the rotation of the complex systems C60 plus 3Li ions, and we found that the T(E) are dependent on the position of ions if it close or far from the electrodes. Finally, the spin polarization of orbital is studied for all ions doped by C60 and we found the ions with ferromagnetic properties like Co and Ni have a higher effect than others.