Spin-Crossover Materials towards Microwave Radiation Switches

Abstract

Microwave electromagnetic radiation that ranges from one meter to one millimetre wavelengths is finding numerous applications for wireless communication, navigation and detection, which makes materials able to tune microwave radiation getting widespread interest. Here we offer a new way to tune GHz frequency radiation by using spin-crossover complexes that are known to change their various physical properties under the influence of diverse external stimuli. As a result of electronic re-configuration process, microwave absorption properties differ for high spin and low spin forms of the complex. The evolution of a microwave absorption spectrum for the switchable compound within the region of thermal transition indicates that the high-spin and the low-spin forms are characterized by a different attenuation of electromagnetic waves. Absorption and reflection coefficients were found to be higher in the high-spin state comparing to the low-spin state. These results reveal a considerable potential for the implementation of spin-crossover materials into different elements of microwave signal switching and wireless communication.

OctaDist: a tool for calculating distortion parameters in spin crossover and coordination complexes

“…Among magnetic compounds, the design of property-controllable spin crossover (SCO) materials remains a key goal of SCO research in part because of their potential in a range of new technologies. [1][2][3][4] Many molecular, 1D, 2D and 3D SCO systems, often based on iron, have been synthesized in recent decades. 5,6 These studies have provided new principles for the design, not only of SCO compounds, but also iron-based catalysts where the reactivity is often spinstate dependent.…”

Reversible Photo- and Thermo-Induced Spin-State Switching in a Heterometallic {5d-3d} W2Fe2 Molecular Square Complex

“…Switchable molecular magnetic materials have been representing an amazing class of systems offering a large range of desired physical properties with enormous potential application in quantum science and technologies, , mainly those exhibiting magnetic, optical, and/or electric bistabilities, which includes spin crossover (SCO), − single molecule magnets (SMMs), − single chain magnets (SCMs), − metal-to-metal electron transfer (MMET), − etc. Switching of the magnetic properties in iron­(II)-based SCO materials originates from their reversible spin-state switching between a low-spin (LS) and high-spin (HS) state upon application of an external stimulus, e.g., temperature, pressure, light irradiation, and magnetic field, with a drastic alteration in electric and optical behaviors. − Importantly, SCO occurring at around or above room temperature is desirable for developing SCO-based electronics and spintronics devices amiable for practical use. ,,− …”

Direct Synthesis of Spin‐Crossover Complexes: An Unexpectedly Revealed New Iron‐Triazolic Structure

“…The most notable changes concern magnetic, optical, [ 2 ] mechanical [ 3 ] and electric [ 4,5 ] properties. As a result, SCO complexes found their numerous applications as actuators, [ 3 ] chemical sensors, [ 6,7 ] switchable catalysts, [ 8 ] microwave radiation switches, [ 9 ] memory displays, [ 10 ] microthermometers, [ 11 ] nanoelectronic devices, [ 12 ] etc. Additionally, inclusion of different molecules in frameworks of SCO compounds leads to a shift of SCO characteristics such as a spin transition temperature and width of hysteresis.…”