Investigations on structural disorder-induced modifications in the transport behaviour of rare-earth manganites

Bulletin of materials science

KEVAL GADANI¹  P S SOLANKI¹  D D PANDYA¹  HETAL BORICHA¹  SANJAY KANSARA¹  J H MARKNA²  N A SHAH¹  DAVIT DHRUV³  ZALAK JOSHI¹ 

[1] Department of Physics, Saurashtra University, Rajkot 360 005, India$$Department of Physics, Saurashtra University, Rajkot 360 005, IndiaDepartment of Physics, Saurashtra University, Rajkot 360 005, India$$;V.V.P. Engineering College, Gujarat Technological University, Rajkot 360 005, India$$V.V.P. Engineering College, Gujarat Technological University, Rajkot 360 005, IndiaV.V.P. Engineering College, Gujarat Technological University, Rajkot 360 005, India$$;Department of Physics, Saurashtra University, Rajkot 360 005, India$$V.V.P. Engineering College, Gujarat Technological University, Rajkot 360 005, India$$Department of Physics, Saurashtra University, Rajkot 360 005, IndiaDepartment of Physics, Saurashtra University, Rajkot 360 005, India$$V.V.P. Engineering College, Gujarat Technological University, Rajkot 360 005, India$$V.V.P. Engineering College, Gujarat Technological University, Rajkot 360 005, IndiaDepartment of Physics, Saurashtra University, Rajkot 360 005, India$$V.V.P. Engineering College, Gujarat Technological University, Rajkot 360 005, India$$

关键词: Manganites;    structural disorder;    transport behaviour;    phase segregation.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

The results of the studies on structural disorder-induced modifications in the transport behaviour of La$_{0.5}$Pr$_{0.2}$Ca$_{0.3−x}$Ba$_x$MnO$_3$(LPCBMO) ($0.05 �? x �? 0.30$) manganites were reported. Structural studies using X-ray diffraction (XRD) measurements confirmed the single phasic nature of all the samples without any detectable impurities. The A-site size disorder ($σ_2$ A) increased from $3.81 imes 10^{�?5} (x = 0.05)$ to $14.9 imes 10�?5 (x = 0.30)$. With the increase in structural disorder in LPCBMO system, the transport improved for the range: $0.15 �? x �? 0.30$, which can be ascribed to the enhancement in one electron bandwidth which dominates over the structural disorder effect, while for lower values of $x$, strong competition existed between size disorder and one electron bandwidth. Below 50 K, all $ho�?�T$ plots showed resistivity minimum behaviour, which modified with disorder. This behaviour wasdiscussed in detail on the basis of electron�?�electron interaction having the form: $ho = [1/(ho_0 + BT^{1/2})] + ho_nT_n$. Variation in temperature sensitivity with disorder was also discussed in context of granular morphology and phasesegregation scenario.

【 授权许可】

Unknown