Structure and transport studies on nanometer YBCO/PBCAO multilayers

Clustering Based Analytical Review for Improving the Quality of Primary Education in MP

“…Different clustering algorithms have been used to group students, such as: hierarchical agglomerative clustering, Kmeans and model based clustering to identify groups of students with similar skill profiles a clustering algorithm based on large generalized sequences to find groups of students with similar learning characteristics based on their traversal path patterns (Tang & Mccalla, 2002). K-means clustering algorithm for effectively grouping students who demonstrate similar learning portfolios (students" assignment scores, exam scores and online learning records) (Chen et. al., 2007).…”

Fabrication,Transport and Raman Studies of Pulsed Laser Deposited Al/Ga Doped PBCO Thin Films

“…Raman spectroscopy has been used to investigate the effect of different metals substitution for Cu (1) or Cu (2) in YBCO by frequency shift of the oxygen vibrations or emergence of new Raman peaks which are otherwise Raman forbidden. Figure 4 shows the Raman spectra of (110) oriented PBCMO (M=0, Al, Ga) thin films.…”

“…At 77 K, Al doped ceramic PBCO showed about four orders in magnitude higher electrical resistivity than in undoped PBCO [1,4]. In our previous experiments, we reported the fabrication of pure phase PrBa 2 (Cu 1-x M x ) 3 O 7 (PBCMO, M=Al, Ga, Co, Ni, Zn and Fe; x=0.05, 0.10, 0.15, 0.20) bulk materials.…”

“…The intrinsic coherence length of YBCO is ~0.5nm along its caxis and ~4 nm along its ab-plane [1]. These S-I-S junctions based on high temperature superconducting (HTSC) materials are operable at or above liquid nitrogen temperature (77K) eliminating an expensive and cumbersome liquid helium (4.2 K) cryogenics.…”

“…The excellent lattice match reduces the strain of the YBCO film in the S-I-S junction and thus preserves its high T c . Experiments, however, show that the resistivity of the ceramic PBCO at 77 K is only about 200 Ω-Cm [2,4], which will be much smaller for thin films and thus can not provide a sufficient potential barrier for a YBCO S-I-S junction at 77 K. Proximity effect has also been observed in PBCO when in contact with YBCO which deteriorates the insulating property in YBCO/PBCO multilayer [1]. Experiments, however, show that the resistivity of the ceramic PBCO at 77 K is only about 200 Ω-Cm [2,4], which will be much smaller for thin films and thus can not provide a sufficient potential barrier for a YBCO S-I-S junction at 77 K. Proximity effect has also been observed in PBCO when in contact with YBCO which deteriorates the insulating property in YBCO/PBCO multilayer [1].…”