المستخلص: |
In this research, samples were prepared by using solid state reaction with starting composition YBa2(Cu1-x Lax)3O7 for x=0.0 , 0.02 . 0.04 and 0.06 . The variation of the structural changes of the lattice parameters (a, b and c/3), orthorhombic distortion and strain of YBa2(Cu1-x Lax)3O7 prepared samples as a function of La concentration (x) within the range of (0 x 0.06) were studied, using XRD measurements. Within this range, all samples showed orthorhombic phase and no phase transition to the tetragonal is observed. An increase of a-parameter is shown due to the substitution of Cu by La which has larger ionic radius. While b-parameter, c/3 parameter, orthorhombic distortion and strain showed similar behavior to each other. All of them decreased to a minimum value at x=0.02, then followed by a successive increase up to x=0.06.
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