Fabrication of Ca-Mn-Nb-O compounds and their structural, electrical, magnetic and thermoelectric properties

Küçük Resim Yok

Tarih

2018

Dergi Başlığı

Dergi ISSN

Cilt Başlığı

Yayıncı

Iop Publishing Ltd

Erişim Hakkı

info:eu-repo/semantics/closedAccess

Özet

CaMn1-xNbxO3-delta (0 <= x <= 1) were synthesized by conventional solid state reaction method. The structural properties were determined by FTIR, Raman, XRD, XAS measurements. The FTIR and Raman modes change by increasing Nb content and the lattice volume increases by increasing Nb content. The solubility limit of Nb is determined as x <= 0.3 and impurity phases start to appear above this limit. The temperature dependence of the magnetization data shows an antiferromagnetic transition below 120 K for low Nb content. Increasing the Nb content causes a change in the magnetic phase from antiferromagnetic to paramagnetic. The oxygen deficiency in CaMnO3-delta may cause the formation of polaron effect which is destroyed by the Nb ions. The difference graph of XAS data for x = 0 and 0.5 show that the number of Mn3+ ions increases by increasing Nb content to maintain the charge neutrality.

Açıklama

Anahtar Kelimeler

CaMnO3, XAS, oxygen deficiency

Kaynak

Materials Research Express

WoS Q Değeri

Q3

Scopus Q Değeri

Q2

Cilt

5

Sayı

3

Künye