In this work, I investigated and studied the CrTe compound, which has a spin amplitude of about 2, to determine its critical behaviors at near room temperature, magnetocaloric cooling, and magnetic ...characteristics. For the purpose of this study, I used the Metropolis algorithm with the Monte Carlo approach. The Curie temperature of CrTe is around 326 K, which is determined through the magnetization M(T) and the inverse magnetic susceptibility (χ−1). The Arrott curves (H/M vs. M2) and the isothermal magnetization M(H) demonstrate a second-order ferromagnetic (FM) to paramagnetic (PM) state phase transition. The magnetic entropy change (-ΔSM), relative cooling power (RCP), and refrigeration capacity (Q) at 8 T are 1.31 J kg⁻1 K⁻1, 106 J kg⁻1, and 79 J kg⁻1, respectively. To calculate the critical exponents of CrTe, I used the Widom scaling relation and the modified Arrott plot (MAP). The critical exponent values were found to be in good agreement with those estimated using the renormalization group approach for a 3D-Ising model.
•The CrTe has been studied.•Thermal magnetization, Inverse susceptibility magnetization of the system have been established.•Transition temperature has been deduced.•Isothermal magnetic entropy change, relative cooling power (RCP) and RC for the different external magnetic field have been examined.•Critical behaviors have been determined.
The discovery of 2D van der Waals (vdW) magnetic materials is of great significance to explore intriguing 2D magnetic physics and develop innovative spintronic devices. In this work, a new quasi‐1D ...vdW layered compound CrZr4Te14 is successfully synthesized. Owing to the existence of 1D CrTe2 and ZrTe3 chains along the b‐axis, CrZr4Te14 crystals show strong anisotropy of phonon vibrations, electrical transport, and magnetism. Density functional theory calculations reveal the ferromagnetic (FM) coupling within the CrTe2 chain, while the interchain and interlayer couplings are both weakly antiferromagnetic (AF). Notably, a large intrinsic negative magnetoresistance (nMR) of −56% is achieved at 2 K under 9 T, and the in‐plane anisotropic factor of nMR can reach up to 8.2 in the CrZr4Te14 device. The 1D FM chains and anisotropic nMR effect make CrZr4Te14 an interesting platform for exploring novel polarization‐sensitive spintronics.
Layered CrZr4Te14 is constructed of CrTe2 and ZrTe3 chains along the b‐axis. The intrachain magnetic coupling of the CrTe2 chain is ferromagnetic, while the opposite magnetic ordering between the chains makes CrZr4Te14 an antiferromagnet. Moreover, CrZr4Te14 shows large intrinsic negative magnetoresistence of −56%, and the in‐plane anisotropic factor reaches 8.2 owing to the ferromagnetic CrTe2 chains.
Although many emerging new phenomena have been unraveled in two dimensional (2D) materials with long-range spin orderings, the usually low critical temperature in van der Waals (vdW) magnetic ...material has thus far hindered the related practical applications. Here, we show that ferromagnetism can hold above 300 K in a metallic phase of 1T-CrTe
2
down to the ultra-thin limit. It thus makes CrTe
2
so far the only known exfoliated ultra-thin vdW magnets with intrinsic long-range magnetic ordering above room temperature. An in-plane room-temperature negative anisotropic magnetoresistance (AMR) was obtained in ultra-thin CrTe
2
devices, with a sign change in the AMR at lower temperature, with −0.6% and +5% at 300 and 10 K, respectively. Our findings provide insights into magnetism in ultra-thin CrTe
2
, expanding the vdW crystals toolbox for future room-temperature spintronic applications.
Chromium telluride (CrTe) has received much attention due to its small magnetic anisotropy, which hosts the potential for complex magnetic structures. However, its magnetic properties have been ...relatively unexplored with numerical simulations, as the magnetic interactions inside are quite unusual. In this study, we employ both a machine-learning model and an empirical model to investigate the magnetic phase transitions of bulk and monolayer CrTe, revealing the existence of unusual magnetic interaction, which can be captured by the machine-learning model but not the simple empirical model. Furthermore, our results also demonstrate that magnetic moments further apart exhibit stronger interactions than those in closer proximity, deviating from typical behavior.
By combining the USPEX evolutionary algorithm and density functional theory at the HSE06 level, we identified a new CrTe2 monolayer crystallizing in monoclinic phase with C2h symmetry, which is ...different from the well-known 1T-CrTe2 monolayer. The monoclinic phase is energetically favored over that in 1T phase, is thermodynamically, dynamically, and mechanically stable. The monoclinic phase is an intrinsically ferromagnetic metal with a relatively high Curie temperature of 215 K showing an out-of-plane easy axis with 25° off the z-axis. In particular, the predicted Curie temperature and out-of-plane ferromagnetic order are in agreement with the experimental evidence. In addition, a uniaxial strain can induce a ferroelastic switching together with the magnetic easy axis, resulting in a strong intrinsic magnetoelasticity. Our results open up a new possibility for the realization of novel two-dimensional ferromagnets and provide a platform for understanding the underlying physical mechanism.
Based on the first-principles calculations, the two-dimensional layers of ferromagnetic materials for monolayer CrTe were investigated. We inspect the effects of electric field and biaxial strain on ...the characteristics of monolayer CrTe to determine its electrical, magnetic, structural, and optical properties. The monolayer CrTe exhibits half-metallic properties where each unit cell's magnetic moment is equivalent to 4 μB. The magnitude of the energy gap in the spin-up channel decreases with screwing strain and increases with compressive strain under the influence of (Sb). The electric field noticeably impacts the energy gap because the half-metallic feature is destroyed when the electric field value is E = 0.9 V/nm. The optical characteristic examinations determine that the material is a strong contender for use in microelectronic and optoelectronic device applications.
•The monolayer CrTe exhibits half-metallic properties.•The material is a strong contender for use in optoelectronic device applications.•The compound CrTe maintains the HM feature in all cases of biaxial strain.
Euglena gracilis, a unicellular phytoflagellate within Euglenida, has attracted much attention as a potential feedstock for renewable energy production. In outdoor open-pond cultivation for biofuel ...production, excess direct sunlight can inhibit photosynthesis in this alga and decrease its productivity. Carotenoids play important roles in light harvesting during photosynthesis and offer photoprotection for certain non-photosynthetic and photosynthetic organisms including cyanobacteria, algae, and higher plants. Although, Euglenida contains β-carotene and xanthophylls (such as zeaxanthin, diatoxanthin, diadinoxanthin and 9'-cis neoxanthin), the pathway of carotenoid biosynthesis has not been elucidated.
To clarify the carotenoid biosynthetic pathway in E. gracilis, we searched for the putative E. gracilis geranylgeranyl pyrophosphate (GGPP) synthase gene (crtE) and phytoene synthase gene (crtB) by tblastn searches from RNA-seq data and obtained their cDNAs. Complementation experiments in Escherichia coli with carotenoid biosynthetic genes of Pantoea ananatis showed that E. gracilis crtE (EgcrtE) and EgcrtB cDNAs encode GGPP synthase and phytoene synthase, respectively. Phylogenetic analyses indicated that the predicted proteins of EgcrtE and EgcrtB belong to a clade distinct from a group of GGPP synthase and phytoene synthase proteins, respectively, of algae and higher plants. In addition, we investigated the effects of light stress on the expression of crtE and crtB in E. gracilis. Continuous illumination at 460 or 920 μmol m(-2) s(-1) at 25 °C decreased the E. gracilis cell concentration by 28-40 % and 13-91 %, respectively, relative to the control light intensity (55 μmol m(-2) s(-1)). When grown under continuous light at 920 μmol m(-2) s(-1), the algal cells turned reddish-orange and showed a 1.3-fold increase in the crtB expression. In contrast, EgcrtE expression was not significantly affected by the light-stress treatments examined.
We identified genes encoding CrtE and CrtB in E. gracilis and found that their protein products catalyze the early steps of carotenoid biosynthesis. Further, we found that the response of the carotenoid biosynthetic pathway to light stress in E. gracilis is controlled, at least in part, by the level of crtB transcription. This is the first functional analysis of crtE and crtB in Euglena.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
2D materials with long‐range ferromagnetic order hold promises for the development of compact spintronic devices with unprecedented multifunctionality and tunability. Among various 2D magnets, ...self‐intercalated transition metal chalcogenides Cr1+δTe2 exhibit unique features, especially excellent ambient stability and intrinsic ferromagnetic ordering above room temperature, which are critical requirements for real‐life device applications. Despite the many investigations of the magnetic properties of the Cr1+δTe2 family on the averaging macroscopic level, the domain evolution on the microscale, which is vital to nanoscale spintronics, is yet to be fully understood. Here, the evolution of magnetic behaviors of Cr0.92Te crystals is presented on both macro‐ and micro‐scales under magnetic field and thermal excitation. The crystal exhibits a high Curie temperature (Tc ≈ 343 K) among the Cr1+δTe2 family with weak magnetic anisotropy and in‐plane magnetic easy axis. Utilizing magnetic force microscopy, a pristine multidomain state and typical domain‐switching behavior are observed. Moreover, the evolution of domain texture under thermal excitation shows statistical power‐law scaling as approaching Tc. The results provide microscopic insight into the ferromagnetic behavior of a room‐temperature quasi‐2D crystal, which can be useful for further engineering of domain texture in low‐dimensional magnetic materials.
Cr0.92Te crystals grown by chemical vapor transport exhibit self‐intercalated quasi‐2D structure and possess high magnetic curie temperature (Tc ≈ 343 K) among the Cr1+δTe2 family. They have weak magnetic anisotropy and an in‐plane magnetic easy axis. Their magnetic domain structure is extremely sensitive to external magnetic fields and thermal excitations.
It is essential to produce oxygen evolution reaction (OER) electrocatalysts, which are active and enduring for water electrolyzers. In order to create the effective OER, new chromium ...telluride/graphitic carbon nitride (gCN/CrTe) is produced via simple hydrothermal method. In this case, catalyst super hydrophilic surface is developed by the addition of 10% gCN nanosheets that can optimize the revelation of active sites and encourage the mass dispersion. Due to the robust contact among CrTe and gCN, which causes a lattice strain and an increase in the electron density around Cr sites, regulating the bonding between the catalyst and chemical intermediates. The improved 10% gCN/CrTe nanocomposite offers not only a good endurance but also by the highest mass activity. The synthesized 10% gCN/CrTe electrocatalysts provided low overpotential around 187 mV for OER to achieve a current density of 10 mA/cm
2
in alkaline media with 51.0 h of long durability. Paving the way for innovative applications, this will enable the manipulation of advanced materials' fundamental properties at the atomic scale.
We have studied the magnetic and electrical transport properties of epitaxial NiAs-type CrTe thin films grown on SrTiO
3
(111) substrates. Unlike rectangle hysteresis loops obtained from magnetic ...measurements, we have identified intriguing extra bump/dip features from anomalous Hall experiments on the films with thicknesses less than 12 nm. This observed Hall anomaly is phenomenologically consistent with the occurrence of a topological Hall effect(THE) in chiral magnets with a skyrmion phase. Furthermore, the THE contribution can be tuned by the film thickness, showing the key contribution of asymmetric interfaces in stabilizing Néel-type skyrmions. Our work demonstrates that a CrTe thin film on SrTiO
3
(111) substrates is a good material candidate for studying real-space topological transport.
PDF
