Structual and Dielectric Properties of Pb(Zr0.53Ti0.47)O3 Thin Films Grown on LaNiO3 Buffered Si Substrates
Ferroelectric Pb(Zr0.53Ti0.47)O3 thin films with thickness of around 800 nm were prepared on LaNiO3 (LNO) buffered SiO2/Si substrates by sol-gel method. The LNO buffer layer serves as the bottom electrode and the template for growing PZT thin films with preferred orientation. The (110)-textured PZT thin films can be obtained on 250 nm-thick LNO buffered SiO2/Si substrates. Upon using the LNO buffer layer, the annealing temperature of the PZT films is lowered to 600degC. Our results indicate that PZT thin films prepared on LNO buffered Si substrates have good structural and dielectric properties for sensor and actuator applications.
Growth of biaxially oriented conductive LaNiO3 buffer layers on textured Ni tapes for high-Tc-coated conductors
Abstract Electrically conductive LaNiO 3 buffer layers have been grown on textured nickel tapes by sputter deposition in a reducing atmosphere. These conductive buffered Ni tapes can be employed as long flexible substrates for biaxially aligned high-temperature superconductors, and can electrically stabilize the superconductor during transient loss of superconductivity. Deposition temperatures of about 400°C result in epitaxial growth of LaNiO 3 films, while higher deposition temperatures may cause the formation of La 2 NiO 4 films. X-ray θ –2 θ , θ , and φ scans reveal that the LaNiO 3 films have good out-of-plane and in-plane orientations of 5° and 9–10°, respectively. Subsequent oxygen anneals at 750°C and 850°C change neither the biaxial orientations of the film nor cause any cracks or other surface defects. The resistivity of the LaNiO 3 films can be further reduced by increasing the annealing temperature and oxygen pressure during post-annealing. Highly textured YBa 2 Cu 3 O 7 (YBCO) films were grown on the LaNiO 3 -buffered Ni by pulsed laser deposition (PLD).
OSBP Is a Cholesterol-Regulated Scaffolding Protein in Control of ERK1/2 Activation
Oxysterol-binding protein (OSBP) is the founding member of a family of sterol-binding proteins implicated in vesicle transport, lipid metabolism, and signal transduction. Here, OSBP was found to function as a cholesterol-binding scaffolding protein coordinating the activity of two phosphatases to control the extracellular signal–regulated kinase (ERK) signaling pathway. Cytosolic OSBP formed a ∼440-kilodalton oligomer with a member of the PTPPBS family of tyrosine phosphatases, the serine/threonine phosphatase PP2A, and cholesterol. This oligomer had dual specific phosphatase activity for phosphorylated ERK (pERK). When cell cholesterol was lowered, the oligomer disassembled and the level of pERK rose. The oligomer also disassembled when exposed to oxysterols. Increasing the amount of OSBP oligomer rendered cells resistant to the effects of cholesterol depletion and decreased the basal level of pERK. Thus, cholesterol functions through its interaction with OSBP outside of membranes to regulate the assembly of an oligomeric phosphatase that controls a key signaling pathway in the cell.