Determination of physical properties for the mixtures of [BMIM]Cl with different organic solvents

Physical properties including refractive index, density, viscosity and conductivity for binary mixtures of l-butyl- 3-methyl imidazolium chloride （[BMIM]CI） and different organic solvents at 298.15 K have been investigated. Ex- cess molar volumes have been calculated and obtained data has been fitted by the Redlich-Kister equation. The density and refractive index were found to increase with increasing concentration of [BMIM]CI, however, excep- tions do exist as in the case of dimethyl sulfoxide （DMSO）/[BMIM]CI. For DMSO/[BMIM]CI, the density decreases with increasing concentration. The addition of different organic solvents was able to disrupt the interactions within mixtures, leading to free mobility of ions. The free mobility of ions has been found to enhance conductivity and decrease viscosity to varying extents in all mixtures studied. It has been observed that solubility parameters, dielectric constants and composition of the solvents used play a vital role in determining the resultant properties. The data obtained will play an important role in understanding the effect of the addition of organic solvents in ILs to enhance their applicability.

Molar volume of eutectic solvents as a function of molar composition and temperature

The conventional Rackett model for predicting liquid molar volume has been modified to cater for the effect of molar composition of the Deep Eutectic Solvents(DES). The experimental molar volume data for a group of commonly used DES has been used for optimizing the improved model. The data involved different molar compositions of each DES. The validation of the new model was performed on another set of DESs. The average relative deviation of the model on the training and validation datasets was approximately 0.1% while the Rackett model gave a relative deviation of more than 1.6%. The modified model deals with variations in DES molar composition and temperature in a more consistent way than the original Rackett model which exhibits monotonic performance degradation as temperature moves away from reference conditions. Having the composition of the DES as a model variable enhances the practical utilization of the predicting model in diverse design and process simulation applications.

Electrical control of antiferromagnetic metal up to 15 nm

Manipulation of antiferromagnetic(AFM) spins by electrical means is on great demand to develop the AFM spintronics with low power consumption. Here we report a reversible electrical control of antiferromagnetic moments of FeMn up to 15 nm, using an ionic liquid to exert a substantial electric-field effect. The manipulation is demonstrated by the modulation of exchange spring in[Co/Pt]/FeMn system, where AFM moments in FeMn pin the magnetization rotation of Co/Pt. By carrier injection or extraction,the magnetic anisotropy of the top layer in FeMn is modulated to influence the whole exchange spring and then passes its influence to the [Co/Pt]/FeMn interface, through a distance up to the length of exchange spring that fully screens electric field. Comparing FeMn to IrMn, despite the opposite dependence of exchange bias on gate voltages, the same correlation between carrier density and exchange spring stiffness is demonstrated. Besides the fundamental significance of modulating the spin structures in metallic AFM via all-electrical fashion, the present finding would advance the development of low-power-consumption AFM spintronics.