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Finding a suitable ferromagnetic transparent semiconducting material is of utmost importance for the development of advanced devices with unique functionalities. Herein, the electronic, magnetic, and optical attributes of bulk and (111) surfaces of cobalt ferrite (CFO) are comprehensively explored through rigorous first-principles calculations. Bulk CFO and (111) thin films of thickness 1-unit cell (1UC) and 2-unit cell (2UC) with Fe terminations have ferrimagnetic semiconducting behavior with band gaps of 1.82 eV (bulk), 0.64 eV (1UC) and 0.54 eV (2UC). Bulk CFO displays an in-plane magnetic anisotropy energy of −35 μeV per atom, whereas both 1UC and 2UC structures with Fe terminations exhibit −60 and −91 μeV per atom. Bulk CFO has a Curie temperature (TC) of 843 K, and the critical temperature is suppressed in thin films. Nonetheless, we still find a Cuire temperature higher than room temperature. For instance, the calculated Curie temperature is 471 K and 582 K for 1UC and 2UC films with Fe terminations. Besides, the 1UC and 2UC thin films of CFO show optical transparency in the visible range with a transmittance of around ∼94 to 96%. These findings suggest the potential of the CFO bulk and surfaces for application in spintronic and optoelectronic devices at elevated temperatures. [ABSTRACT FROM AUTHOR]

In spintronics, transverse anomalous transport properties have emerged as a highly promising avenue surpassing the conventional longitudinal transport behaviors. Here, we explore the transverse transport properties of monolayer and bilayer Fe3−xCoxGaTe2 (x = 0.083, 0.167, 0.250, and 0.330) systems. All the systems exhibit ferromagnetic ground states with metallic features and also have perpendicular magnetic anisotropy. Besides, the magnetic anisotropy is substantially enhanced with increasing Co-doping concentration. However, unlike magnetic anisotropy, the Curie temperature is suppressed by increasing the Co-doping concentration. For instance, the monolayer and bilayer Fe2.917Co0.083GaTe2 hold a Curie temperature of 253 K and 269 K, which decreases to 163 K and 173 K in monolayer and bilayer Fe2.67Co0.33GaTe2 systems, respectively. We find a giant anomalous Nernst conductivity (ANC) of 6.03 A/(K·m) in the monolayer Fe2.917Co0.083GaTe2 at −30 meV, and this is further enhanced to 11.30 A/(K·m) in the bilayer Fe2.917Co0.083GaTe2 at −20 meV. Moreover, the bilayer Fe2.917Co0.083GaTe2 structure has a large anomalous thermal Hall conductivity (ATHC) of −0.14 W/(K·m) at 100 K. Overall, we find that the Fe3−xCoxGaTe2 (x = 0.083, 0.167, 0.250, and 0.330) structures have better anomalous transverse transport performance than the pristine Fe3GaTe2 system and can be used for potential spintronics and spin caloritronics applications. [ABSTRACT FROM AUTHOR]

Transparent two-dimensional (2D) magnetic materials may bring intriguing features and are indispensable for transparent electronics. However, it is rare to find both optical transparency and room-temperature ferromagnetism simultaneously in a single 2D material. Herein, we explore the possibility of both these features in 2D WSe2/1T-VSe2 (1ML)/WSe2 and WSe2/1T-VSe2 (2ML)/WSe2 heterostructures by taking one monolayer (1ML) and two monolayers (2ML) of 1T-VSe2 using first-principles calculations. Further, we investigate anomalous Hall conductivity (AHC) and anomalous Nernst conductivity (ANC) using a maximally localized Wannier function. The WSe2/1T-VSe2 (1ML)/WSe2 and WSe2/1T-VSe2 (2ML)/WSe2 systems show Curie temperatures of 328 and 405 K. Under biaxial compressive strain, the magnetic anisotropy of both systems is switched from in-plane to out-of-plane. We find a large AHC of 1.51 e2/h and 3.10 e2/h in the electron-doped region for strained WSe2/1T-VSe2 (1ML)/WSe2 and WSe2/1T-VSe2 (2ML)/WSe2 systems. Furthermore, we obtain a giant ANC of 3.94 AK−1 m−1 in a hole-doped strained WSe2/1T-VSe2 (2ML)/WSe2 system at 100 K. Both WSe2/1T-VSe2 (1ML)/WSe2 and WSe2/1T-VSe2 (2ML)/WSe2 are optically transparent in the visible ranges with large refractive indices of 3.2–3.4. Our results may suggest that the WSe2/1T-VSe2/WSe2 structure possesses multifunctional physical properties and these features can be utilized for spintronics and optoelectronics device applications such as magnetic sensors, memory devices, and transparent magneto-optic devices at room temperature. [ABSTRACT FROM AUTHOR]

Anomalous transverse conductivities, such as anomalous Hall conductivity (AHC), anomalous Nernst conductivity (ANC), and anomalous thermal Hall conductivity (ATHC), play a crucial role in the emerging field of spintronics. Motivated by the recent fabrication of two-dimensional (2D) ferromagnetic thin film Fe3GaTe2, we investigate the thickness-dependent anomalous transverse conductivities of the 2D Fe3GaTe2 system (from one to four layers). The atomically ultrathin 2D Fe3GaTe2 system shows above-room-temperature ferromagnetism with a large perpendicular magnetic anisotropy energy. Furthermore, we obtain a large AHC of −485 S/cm in the four-layer thickness, and this is further enhanced to −550 S/cm with small electron doping. This AHC is seven times larger than the measured AHC in thicker 2D Fe3GaTe2 (178 nm). The ANC also reaches 0.55 A/K.m in the four-layer structure. Along with these, the four-layer system exhibits a large ATHC (−0.105 ~ −0.135 W/K.m). This ATHC is comparable to the large ATHC found in Weyl semimetal Co3Sn2S2. Based on our results, the atomically ultrathin 2D Fe3GaTe2 system shows outstanding anomalous transverse conductivities and can be utilized as a potential platform for future spintronics and spin caloritronic device applications. Ultrathin 2D Fe3GaTe2: A Game-Changer in Future Spintronics Two-dimensional materials have become popular in science due to their unique characteristics and potential for new technologies. In this study, researchers examined a specific 2D material, Fe3GaTe2, which has shown potential due to its strong magnetism at high temperatures, making it suitable for spintronics devices that operate at room temperature or above. The team performed calculations to investigate how the thickness of Fe3GaTe2 layers impacts their magnetic and anomalous transport properties. In conclusion, the study showed that adding more layers to the Fe3GaTe2 single layer improves its anomalous transverse conductivities, which could lead to better performance in future spintronic devices. The findings suggest that ultra-thin layers of this material could be very useful in the field of spintronics, potentially leading to more efficient and powerful technology. This summary was initially drafted using artificial intelligence, then revised and fact-checked by the author. We investigate the anomalous transverse conductivities of a two-dimensional (2D) magnetic Fe3GaTe2 system (monolayer to four-layer thickness). A giant anomalous thermal Hall conductivity (ATHC) of -0.14 W/K.m is obtained in the four-layer structure, and this value is comparable to the typical ATHC found in bulk materials which is rare to find in low-dimensional systems. Our findings suggest that the ultra-thin 2D Fe3GaTe2 system could be a promising platform for future spintronics and spin caloritronics device applications. [ABSTRACT FROM AUTHOR]