Effect of yttrium substitution on the electrical and magnetic properties of La_0.7Ba_0.3MnO₃ compound

In the recent years manganese oxides La_0.7A_0.3MnO₃ (A=Ca, Sr and Ba) received great attention because of their unique electrical and magnetic properties. Colossal changes in the magneto resistance upto the order of 10⁶–10⁸ have been observed in thin films, single crystals and bulk materials. We have studied the effect of Yttrium substitution on the electrical and magnetic properties of La_0.7Ba_0.3MnO₃ compound. Samples of the composition La_0.7−xY_x Ba_0.3MnO₃ with x=0.0–0.4 were prepared using solid state reaction method. XRD patterns of these samples show the single phase nature of the samples. Electrical resistance of samples was measured in the presence of zero and various applied magnetic fields. All the samples have shown a metal–insulator transition and Yttrium substitution has resulted in a systematic decrease in this transition temperature T_MI. Magneto resistance of samples was also found to increase with Yttrium substitution. Susceptibility measurements on these samples have indicated a ferro-paramagnetic transition. The results are discussed in terms of size effects and changes in Mn³⁺–O–Mn⁴⁺ bond angle. - Highlights: • We have studied the effect of Yttrium substitution on the electrical and magnetic properties of La_0.7Ba_0.3MnO₃ compound. • Samples of the composition La_0.7−xY_x Ba_0.3MnO₃ with x=0.0 to 0.4 were prepared using solid state reaction method. • XRD patterns of these samples show the single phase nature of the samples upto x=0.3. • Electrical resistance of samples was measured in the presence of zero and various applied magnetic fields. • Magneto resistance of samples was also found to increase with Yttrium substitution. Susceptibility measurements on these samples have indicated a ferro-paramagnetic transition. The results are discussed in terms of size effects and changes in Mn³⁺–O–Mn⁴⁺ bond angle