New tunneling data are reported in underdoped Bi2Sr2CaCu2O8−δ using superconductor-insulator-superconductor break junctions. Energy gaps, ∆, of 51±2, 54±2 and 57±3 meV are observed for three crystals with Tc=77, 74, and 70 K respectively. These energy gaps are nearly three times larger than for overdoped crystals with similar Tc. Detailed examination of tunneling spectra over a wide doping rang...

In this research DFT/B3LYP method has been employed to investigate the geometrical structures,relative stabilities, and electronic properties of Cun (n=3–10) clusters for clarifying the effect of sizeon the properties. Through a careful analysis of the successive binding energies, second-orderdifference of energy and the highest occupied-lowest unoccupied molecular orbital energy gaps as afunct...