Novel Strategy toward Chromium-Based Thiospinel Multifunctional Magnetic Materials from Amorphous Chromites

Abstract

Magnetic nanomaterials have a broad range of promising applications in mechanical, electronic, optical, magnetic, chemical, and biological fields due to their excellent physicochemical properties, especially their unique magnetic properties. Chromium-based chalcospinels exhibit a variety of magnetic and electrical properties and attract widespread attention. Although the physical properties of Cr-based chalcospinels have been extensively studied, the fabrication of their micro/nanostructures has always been a challenge. In the present work, we develop a novel method for the preparation of Cr-based chalcospinels. The representative ferrimagnetic semiconductor CoCr 2 S 4 , ferromagnetic metal CuCr 2 S 4 , and ferromagnetic semiconductor CdCr 2 S 4 are successfully synthesized by direct sulfurization in a solvothermal system using amorphous metal chromites as the precursors. The phase structure, chemical composition, crystal morphology, optical absorption, and magnetic properties of the obtained samples are analyzed comprehensively. The experimental results demonstrate that the prepared CoCr 2 S 4 and CdCr 2 S 4 samples have direct band gaps of 1.71 and 2.49 eV, and their Curie temperatures are about 206 and 90 K, respectively, while the Curie temperature of the CuCr 2 S 4 sample is higher than room temperature. More importantly, the as-established synthesis methodology is expected to be further extended to other Cr-based chalcospinels, thus opening a new avenue for the potentially universal preparation of this material system.

CoCr2O4 Nanoparticles with Abundant Oxygen Vacancies: A New Photothermal Platform for Efficient Solar Evaporation

“…The characteristic peaks at 780.1 and 795.7 eV can be attributed to the Co 2p 3/2 and Co 2p 1/2 spin orbitals of Co 2+ , respectively, while the two weak peaks at 786.2 and 802.5 eV correspond to the satellite peaks of Co 2p 3/2 and Co 2p 1/2 . In Figure C, the strong peaks at 576.1 and 586.0 eV are designated as Cr 2p 3/2 and Cr 2p 1/2 spin orbitals, respectively, indicating that the element Cr is present in the trivalent state . As shown in Figure D, the spectral data of the O 1s spectrum can be fitted into three characteristic peaks.…”

“…45 In Figure 3C, the strong peaks at 576.1 and 586.0 eV are designated as Cr 2p 3/2 and Cr 2p 1/2 spin orbitals, respectively, indicating that the element Cr is present in the trivalent state. 46 As shown in Figure 3D, the spectral data of the O 1s spectrum can be fitted into three characteristic peaks. The first peak at the lowest binding energy of 529.9 eV is assigned to the lattice oxygen (O latt ), while the second peak at 530.8 eV is ascribed to the adsorbed oxygen (O ads ), due to the adsorption of oxygen species on the oxygen vacancies to stabilize the oxygen vacancies, and the third peak at the highest binding energy of 532.2 eV is associated with the chemisorbed water molecules.…”

Comparative study on the magnetic properties of Fe-substituted Co2Sn1−x Fe x O4 spinel oxides and its exchange bias effect

“…Exchange-biased materials are employed in magnetic field sensors because of their exceptional sensitivity and stability. This is crucial for a wide range of applications, infruscluding automobile sensors and medicinal imaging devices [17,18]. SGs are valuable for investigating the boundaries of magnetic ordering and comprehending the consequences of disorder in crystalline materials.…”

Comparative study on the magnetic properties of Fe-substituted Co2Sn1-xFexO4 spinel oxides and its exchange bias effect

“…Their exible elemental composition and large physiochemical characteristics make them excellent for multifunctional devices [16]. Moreover, magnetic spinel compounds have also been observed to be promising results in biomedicine, such as in magnetic resonance imaging (MRI) [17,18] and as heating mediators in magnetic uid hyperthermia [19,20]. Several studies on the preparation of magnetic spinel compounds and magnetic saturation points have already been reported.…”