<i>In situ</i> x-ray absorption and photoelectron spectroscopy on epitaxial <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Fe</mml:mi><mml:mi>x</mml:mi></mml:msub><mml:mi>Te</mml:mi></mml:mrow></mml:math> thin fi

<a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:msub><a:mi>Fe</a:mi><a:mi>x</a:mi></a:msub><a:mi>Te</a:mi></a:mrow></a:math> thin films were prepared on <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:msub><b:mi>SrTiO</b:mi><b:mn>3</b:mn></b:msub></b:math> (001) substrates by molecular beam epitaxy in a well-ordered epitaxial layer-by-layer fashion. The composition of the films was varied by adjusting the Te flux in a Te-limited growth regime. Changes in the electronic structure were systematically studied using x-ray absorption spectroscopy at the Fe <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"><c:msub><c:mi>L</c:mi><c:mrow><c:mn>2</c:mn><c:mo>,</c:mo><c:mn>3</c:mn></c:mrow></c:msub></c:math> and Te <d:math xmlns:d="http://www.w3.org/1998/Math/MathML"><d:msub><d:mi>M</d:mi><d:mrow><d:mn>4</d:mn><d:mo>,</d:mo><d:mn>5</d:mn></d:mrow></d:msub></d:math> edges and x-ray photoelectron spectroscopy of core levels and valence band. We found that FeTe with optimized composition (Fe/Te ratio <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"><e:mo>≈</e:mo></e:math> 1) provides the sharpest spectral features, indicating that <f:math xmlns:f="http://www.w3.org/1998/Math/MathML"><f:mrow><f:msub><f:mi>Fe</f:mi><f:mrow><f:mn>1.00</f:mn></f:mrow></f:msub><f:mi>Te</f:mi></f:mrow></f:math> can be synthesized as a thin film, although it is not possible in bulk. Published by the American Physical Society 2024