טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentDubinsky Stanislav
SubjectInvestigation of Ionic Polymer/Metal Salt Solutions and
Films
DepartmentDepartment of Materials Science and Engineering
Supervisor Professor Michael Silverstein


Abstract

  Polymers that complex with metal ions from nitrate salts can be used as castable precursors for the production of high temperature superconductor (HTSC) ceramic films. If the polymers are UV sensitive, they can be patterned using lithography prior to pyrolysis in order to form HTSC microbridges. Little is known regarding the degradation of the polymer/metal-salt precursors during HTSC processing. In this investigation the degradation of films cast from solutions containing poly(acrylic acid) (PAAc) and metal salts was characterized using thermogravimetric analysis, differential thermal analysis, differential scanning calorimetry, mass spectrometry and Fourier transform infrared spectroscopy. The thermal degradation of  PAAc/(YBaCu-nitrates) is a complicated multistage process. There are six degradation stages in argon and four stages in air.

The metal nitrates had a profound effect on the mechanism of polymer degradation and significantly lowered the degradation temperature. Initial heating in Ar seems to hinder the formation of oxides from the individual metals. A final heating in air oxidizes the remaining carbon and the metal atoms.

The superconducting YBCO phase was detected in pyrolysed precursor films cast from polymer solutions containing copper, yttrium and barium nitrates with the metals in a 1:2:3 molar ratio.