Abstract
A systematicstudyofthechemicalinteractionofBa2YCu3O6+y and Gd3NbO7 was conductedundertwo
processingconditions:purifiedair(21% po2 ), and100Pa po2 (0.1% po2 ). Phasespresentalongthepseudo-
binaryjoinBa2YCu3O6z and Gd3NbO7 werefoundtobeintwofive-phasevolumeswithinthe
BaO12
Y2O312
Gd2O3Nb2O5CuOy system. Threecommonphasesthatarepresentinallsamplesare
(Y,Gd)2Cu2O5, Ba(Y,Gd)2CuO5 and Cu2O orCuO(dependingontheprocessingconditions).The
assembliesofphasescanbecategorizedinthreeregions,withBa2YCu3O6+y: Gd3NbO7 ratiosof
(I)o5.5:4.5;(II)=5.5:4.5;and(III)45.5:4.5.Thelowestmeltingtemperatureofthesystemwas
determinedtobe E938 1C inair,and850 1C at100Pa po2 . Structuredeterminationsoftwoselected
phases,Ba2(GdxY1x)NbO6 (Fm3¯ m, No.225),and(GdxY3x)NbO7 (C2221, No.20and Ccmm, No.63),
were completedusingtheX-rayRietveldrefinementtechnique.ReferenceX-raypowderdiffraction
patternsforselectedphasesofBa2(GdxY1x)NbO6 (x=0.2,0.4,0.6,and0.8)and(GdxY3x)NbO7 (x=0.6,
1.2, 1.8,2.4and3)havebeenpreparedforinclusioninthePowderDiffractionFile(PDF).
