Torres Jorge, Thakur Sangeeta, Ossinger Sascha, Kumberg Ivar, Golias Evangelos, Trommer Clara W A, Hadjadj Sebastien E, Walter Marcel, Gördes Jendrik, Grunwald Jan, Hosseinifar Rahil, Luo Chen, Kipgen Lalminthang, Radu Florin, Tuczek Felix, Kuch Wolfgang
Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany.
Institut für Anorganische Chemie, Christian-Albrechts Universität zu Kiel, Max-Eyth-Straße 2, 24118 Kiel, Germany.
J Phys Condens Matter. 2025 Jul 29;37(31). doi: 10.1088/1361-648X/adf0d2.
We investigated the properties of the[Fe{H2B(pz)(pypz)}2]spin-crossover complex deposited on highly oriented pyrolytic graphite (HOPG) by x-ray absorption spectroscopy in the temperature range from 10 to 350 Kfor sample thicknesses from 0.9(1) to 1.3(2) ML. The highest temperature at which light can excite the system to a long-lived metastable high-spin (HS) state () and the temperature at which a thermal spin transition occurs (1/2) for the thin film samples are found as about 45 and 325 K, respectively, in agreement with the bulk values. The bulk phase has previously been studied by magnetic susceptibility measurements where it was found that two different polymorphic modifications exist. These findings suggest a potential correlation betweenand the high1/2 from the different film thicknesses of the tridentate[Fe{H2B(pz)(pypz)}2]spin-crossover molecule, with thinner samples exhibiting lower1/2 values. Finally, the highest HS fraction achieved for[Fe{H2B(pz)(pypz)}2]is 0.77 for samples of 0.9(1) and 1.1(1) ML on HOPG at 10 Kand constant light irradiation.
我们通过X射线吸收光谱法研究了沉积在高度取向热解石墨（HOPG）上的[Fe{H₂B(pz)(pypz)}₂]自旋交叉配合物的性质，温度范围为10至350 K，样品厚度为0.9(1)至1.3(2) ML。对于薄膜样品，发现光能够将系统激发到长寿命亚稳态高自旋（HS）态的最高温度（）以及发生热自旋转变的温度（1/2）分别约为45 K和325 K，这与体相值一致。此前已通过磁化率测量对体相进行了研究，发现存在两种不同的多晶型变体。这些发现表明，对于三齿[Fe{H₂B(pz)(pypz)}₂]自旋交叉分子不同薄膜厚度的和高1/2之间可能存在相关性，较薄的样品表现出较低的1/2值。最后，在10 K和恒定光照射下，HOPG上0.9(1)和1.1(1) ML样品的[Fe{H₂B(pz)(pypz)}₂]实现的最高HS分数为0.77。
