Anomalous Nernst effect dependence on composition in Fe _{100− <i>X</i>} Rh <i> _X </i> alloys

Abstract

Abstract We studied the anomalous Nernst effect (ANE) in CsCl-type Fe 100− X Rh X ( X = 45, 48, 50, 52, 54, 60) with a thickness of 50 nm deposited on a thermally oxidized Si substrate. Samples with X &lt; 48 certainly have a ferromagnetic phase, exhibiting the ANE. The composition dependence of the anomalous Nernst coefficient <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>S</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>y</mml:mi> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> </mml:math> agreed with the transverse thermoelectric conductivity <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>α</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>y</mml:mi> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> <mml:mo>.</mml:mo> </mml:math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo stretchy="false">∣</mml:mo> <mml:msub> <mml:mrow> <mml:mi>S</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>y</mml:mi> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> <mml:mo stretchy="false">∣</mml:mo> </mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo stretchy="false">∣</mml:mo> <mml:msub> <mml:mrow> <mml:mi>α</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>y</mml:mi> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> <mml:mo stretchy="false">∣</mml:mo> </mml:math> were maximized at X = 48, which has a ferromagnetic state close to the phase transition state. The maximization of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo stretchy="false">∣</mml:mo> <mml:msub> <mml:mrow> <mml:mi>α</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>y</mml:mi> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> <mml:mo stretchy="false">∣</mml:mo> </mml:math> at X = 48 can be explained using band structure-based calculations, where <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo stretchy="false">∣</mml:mo> <mml:msub> <mml:mrow> <mml:mi>α</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>y</mml:mi> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> <mml:mo stretchy="false">∣</mml:mo> </mml:math> rapidly increases near the phase transition.