Kazuo Nozaki

Abnormal Tc change of Bi1.6Pb0.4Sr2Ca2(Cu1−zTiz)3Ox (0.01<z<0.1)

Influence of Ti addition (substitution for Cu) on Tc is studied for high Tc Bi1.6Pb0.4Sr2Ca2(Cu1−zTiz)3Ox. An abnormal Tc change is found between z=0.01 and 0.1. Based on results of the electrical resistivity and x‐ray diffraction, the abnormal Tc change is discussed.

Influence of Ti addition on Tc of Bi1.6Pb0.4Sr2Ca2Cu3Ox

Abstract Dependences of Ti addition on T off c are investigated for Bi 1.6 Pb 0.4 Sr 2 Ca 2 Cu 3 O x . Limits of Ti addition ( (compositional substitution for Cu, Pb, Bi, Sr and Ca) to maintain the high T off c are defined. Using the X-ray diffraction and electrical results, the dependences of Ti addition on T off c are discussed.

Abnormal Jc changes against temperature of the Bi1.6Pb0.4Sr2Ca2Cu3Ox

The temperature dependence of the superconducting critical current density (Jc) is investigated for the high Tc Bi1.6Pb0.4Sr2Ca2Cu3Ox. An abnormal Jc change is found from 50 to 80 K.

Critical addition of Ti to maintain the Tc of (Bi1-zTiz)1.6Pb0.4Sr2Ca2Cu3Ox above 100 K

Influence of Ti addition (substitution for Bi) on Tc is studied for high Tc (Bi1-zTiz)1.6Pb0.4Sr2Ca2Cu3Ox. We found a critical Ti addition to keep high Tc (above 100 K) of the (Bi1-zTiz)1.6Pb0.4Sr2Ca2Cu3Ox. The high-Tc phase can be found up to 0.5 of z. It is explained by an abnormal Tc change which is found from 0.3 to 0.5 of z. Based on results of the electrical resistivity and x-ray diffraction, an abnormal Tc change is discussed.

Effect of liquid-quenching on the heat treatment time to achieve a Tc of 100 K for Bi1.6Pb0.4Sr2Ca2Cu3Ox

Abstract A high T c is found for liquid-quenched samples after a heat treatment. The heat treatment time to achieve a T c of 100 K is about 6.48×10 4 s for a liquid-quenched sample. It is shorter than that (1.80×10 5 s) for sintered samples. Based on diffractional and electronic discussions, the change in T c can be explained.

Effect of equiaxial microplastic deformation before final annealing on Tc of liquid-quenched Bi1.6Pb0.4Sr2Ca2Cu2.7Ti0.3Ox crystallized

The influence of the treatment (equiaxial microplastic deformation and final annealing) on the Tc0value is studied for the liquid-quenched Bi1.6Pb0.4Sr2Ca2Cu2.7Ti0.3Ox which is crystallized. The treatment increases the Tc0value. Based on results of X-ray diffraction and electrical resistivity, the Tc0change is discussed.

IMPROVEMENT OF BRITTLENESS BY Ti ADDITION FOR HIGH Tc Bi OXIDE

When Ti atoms are substituted for Cu atoms in the high Tc phase, the Ti addition improves ductility without the Tc decreasing. Based on results of lattice constants, the influences of the Ti substitution on ductility are discussed.

TEMPERATURE DEPENDENT Jc OF Ti ADDED Bi-Pb-Sr-Ca-Cu-O

The abnormal Jc increasing against temperature is found from 60 K to 80 K for Ti added BiPbSrCaCuO. The weak magnetic field largely decreases the abnormal Jc values, although the Jc value below 50 K does not largely decrease by the weak magnetic field.

EFFECT OF TITANIUM SUBSTITUTION ON DUCTILITY FOR LIQUID- QUENCHED Bi-Pb-Sr-Ca-Cu-O GLASS

Effects of Ti substitutions for the Bi, Pb, Sr, Ca and Cu atoms on ductility are found for the liquid- quenched Bi oxide glasses. The Ti additions increases ductility. When the Ti atoms substitute for the Sr atoms, the Ti addition strongly enhances the ductility.

Influence of Thermal Hysteresis on Tcmid — (about 115 K) of High-Tc Bi-System

The Tc decay is found by the thermal hysteresis below 300 K of the high Tc (Tc mid about 150 K) Bi-Pb-Sr-Ca-Cu-O. On the other hand, the thermal hysteresis below 150 K doesn’t decrease the Tc value. The life of the high Tc is 6 times of the thermal hysteresis below 200 K. Based on the results of the electrical resistivity, the Tc value change is discussed.