Reaction Sintering Process in Granular Composites: Application to a Superconductor/Ferrite System

✍ Scribed by Agnieszka Kopia-Zastawa; Jean-Raymond Gavarri; Ireneusz Suliga; Marie-Angèle Fremy; Marie-Hélène Pischedda; Stanislawa Jasienska

• Book ID: 102609059
• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 406 KB
• Volume: 145
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1999.8279

✦ Synopsis

Granular superconductor+ferrite (S/F) composites have been fabricated using various sintering conditions (volume fraction 0 of ferrite, volume fraction 0 of superconductor, sintering temperature T sint , sintering time t sint ). The superconducting S phase is the well-known Bi (Pb)+2223 phase (T c ‫؍‬ 110 K). The ferrite (F) is NiFe 2 O 4 . The reaction sintering process is experimentally described by determining the volume fractions of residual S and F phases from X-ray di4raction experiments. Magnetic measurements are used to analyze the degradation process in both residual ferrite and superconducting phases. Nonlinear evolutions of the and residual volume fractions as a function of initial compositions are observed. To interpret these results, we propose to express the chemical kinetics using two elemental reactions such as: F؉n. SPP and S؉SPP. Using various types of kinetics parameters, the solid state reaction in each composite can be modeled as a function of the initial 0 and 0 volume fractions.