Formation and stability of HgCaO2, a competing phase in the synthesis of Hg1−xRexBa2Ca2Cu3O8+δ superconductor

The Influence of Oxygen Partial Pressure on Growth of the (Hg,Re)-1223 Intergrain Junction

“…For all samples, the (Hg,Re)-1223 phase was the main phase present (96%), and slight impurities were detected [14]. In addition, the overdoped sample presented a trace of the HgCaO composition, which is in accordance with Sin et al [19]. The ac magnetic susceptibility of the samples revealed and K. The results suggest that the samples have similar oxygen contents and are in agreement with the [15].…”

“…Regarding this, X-ray powder diffraction pattern (XRD) analysis of each precursor preparation step was done in order to evaluate the oxygen content of the ceramic precursor, as shown in Fig. 1 [19], and as a consequence, this favors the superconductor synthesis. This change of behavior in the peaks has also been observed by Sin et al [15] in precursor samples, where different thermal treatments were applied.…”

Thermogravimetric Study of MHgO2 (M=Ca, Sr, Ba) under Controlled Oxygen and Mercury Partial Pressures and Related Thermodynamics

“…The following values of the decomposition enthalpy and entropy were determined: r H3 2 "160.0$8.6 kJ/mole, r S3 2 "192.1$9.5 J/K ) mole for CaHgO 2 at 830 K and r H3 2 "200.0$8.0 kJ/mole, r S3 2 "229.1$9.1 J/K ) mole at 873 K for BaHgO . Sin et al (7) used the thermobaric analyzer (TBA) for the total vapor pressure measurement over a CaHgO /CaO mixture. The enthalpy and entropy of the reaction Eq.…”

Structural and Superconducting Properties of Hg0.75Re0.25Ba2−xSrxCa2Cu3O8+δ Superconductors Grown by Sol–Gel and Sealed Quartz Tube Synthesis

“…The "lling factor referring to the ratio between the sample mass and the capsule volume is &1.0 g/cm. The thermal treatment starts with the introduction of the sample into a preheated furnace at 8503C to avoid the formation of HgCaO (14). The holding time was 10 h at this maximum temperature.…”