• Sagdeo, Archna
• Surampalli, Akash
• Reddy, V. R.
• Kumar, Kranti
• Prajapat, Deepak
• Das, Pradip

Abstract

<jats:title>Abstract</jats:title><jats:p>Here we report the evidence of an additional magnetic ordering and frequency dispersive magneto-dielectric (MD) permittivity besides multiferroic behavior in Te<jats:sup>4+</jats:sup> (<jats:italic>S</jats:italic> = 0) doped FeVO<jats:sub>4</jats:sub>. Two antiferromagnetic transitions similar to FeVO<jats:sub>4</jats:sub> at ∼21.86 K (T<jats:inline-formula><jats:tex-math><?CDATA $_{N1}$?></jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:msub><mml:mi> </mml:mi><mml:mrow><mml:mi>N</mml:mi><mml:mn>1</mml:mn></mml:mrow></mml:msub></mml:math><jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cmacb0a4ieqn2.gif" xlink:type="simple" /></jats:inline-formula>) and 16.03 K (T<jats:inline-formula><jats:tex-math><?CDATA $_{N2}$?></jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:msub><mml:mi> </mml:mi><mml:mrow><mml:mi>N</mml:mi><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:math><jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cmacb0a4ieqn3.gif" xlink:type="simple" /></jats:inline-formula>) were observed in all samples. An additional novel defect clusters based magnetic ordering at relatively higher temperature (T<jats:inline-formula><jats:tex-math><?CDATA $_{AMO}$?></jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:msub><mml:mi /><mml:mrow><mml:mi>A</mml:mi><mml:mi>M</mml:mi><mml:mi>O</mml:mi></mml:mrow></mml:msub></mml:math><jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cmacb0a4ieqn4.gif" xlink:type="simple" /></jats:inline-formula>) ∼ 203 K is also observed from the magnetization. Evaluated magnetic moments show systematic decrease and the magnetic frustration factors show an increase with the increasing of Te<jats:sup>4+</jats:sup> (<jats:italic>S</jats:italic> = 0) content. MD studies show stable ferroelectric ordering at spiral magnetic transition (T<jats:inline-formula><jats:tex-math><?CDATA $_{N2}$?></jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:msub><mml:mi /><mml:mrow><mml:mi>N</mml:mi><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:math><jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cmacb0a4ieqn5.gif" xlink:type="simple" /></jats:inline-formula>) and the multiferroic order persists to the largest doping of Te (<jats:italic>x</jats:italic> = 0.10). The MD studies also reveal a magneto-capacitive (MC) behavior at T<jats:inline-formula><jats:tex-math><?CDATA $_{AMO}$?></jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:msub><mml:mi /><mml:mrow><mml:mi>A</mml:mi><mml:mi>M</mml:mi><mml:mi>O</mml:mi></mml:mrow></mml:msub></mml:math><jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cmacb0a4ieqn6.gif" xlink:type="simple" /></jats:inline-formula> (∼203 K) with a high dielectric constant and loss, and the possible reason for the magnetic ordering and MC behavior is ascribed to short range magnetic clustering arising out of defect based mechanisms. Mössbauer spectroscopic studies confirm local structural correlation with magnetic and ferroelectric ordering.</jats:p>

Topics

• impedance spectroscopy
• cluster
• dielectric constant
• molecular dynamics
• defect
• magnetization
• clustering