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Herein, the magnetic properties and elastocaloric effects of Cu70Al19 + 0.5xMn11−0.5x (x = 0, 1, 2, 3) alloys are investigated. The resistance versus temperature curves indicate that the phase transition temperature increases as the Mn content decreases. In particular, the Cu70Al20.5Mn9.5 alloy exhibits a phase transition temperature close to room temperature. Therefore, the elastocaloric effects of this alloy are examined under stresses ranging from 200 to 500 MPa. The results show that the adiabatic temperature change of the alloy under a stress of 500 MPa reaches 9.8 K. Furthermore, the magnetization curves at 300 K reveal that the magnetic properties of the alloy significantly improve after undergoing low‐temperature aging treatment. The X‐ray diffraction patterns show that this improvement can be attributed to the transformation of the β1 phase to the ferromagnetic phase β3. Overall, the Cu70Al20.5Mn9.5 alloy demonstrates elastocaloric and magnetic properties comparable to those observed in certain Ni–Mn‐based alloys. [ABSTRACT FROM AUTHOR]

The magnetic properties and the existence of spin reorientation have been systematically investigated in MnNiGa ribbons. The thermomagnetic curve reveals that as-spun and annealed ribbons undergo a two-step magnetic structural transformation and the magnetic properties of the annealed ribbons are improved. The splitting behaviour of zero-field-cooled and filed-cooled (ZFC-FC) curve shows that the ribbon has occurred a spin reorientation transformation. The ZFC and isothermal magnetization curves tested by changing the direction of the magnetic field illustrate the existence of magnetic anisotropy, and the direction of H// is easily magnetized. In the direction of easy magnetization, the value of magnetic entropy is about 1.54 J/kg K. The easy magnetization direction is proved to be in-plane by the decrease of the magnetic domain phase shift. It is clear that the magnetoresistance is negative in all temperature ranges and the nonlinear variation at low fields accounts for the presence of spin reorientation. The variation of Hall resistance curve in a low magnetic field reflects the existence of an abnormal Hall effect. [ABSTRACT FROM AUTHOR]

To enhance the microbial fuel cell (MFC) for wastewater treatment and chemical oxygen demand degradation, TiO2 nanotubes arrays (TNA) are successfully synthesized on Ti foil substrate by the anodization process in HF and NH4F solution, respectively (hereafter, denoted as TNA‐HF and TNA‐NF). The differences between the two kinds of TNA are revealed based on their morphologies and spectroscopic characterizations. It should be highlighted that 3D TNA‐NF with an appropriate dimension can make a positive contribution to the high photocatalytic activity. In comparison with the TNA‐HF, the 3D TNA‐NF sample exhibits a significant enhancement in current generation as the MFC anode. In particular, the TNA‐NF performs nearly 1.23 times higher than the TNA‐HF, and near twofold higher than the carbon felt. It is found that the two kinds of TiO2‐based anodes have different conductivities and corrosion potentials, which are responsible for the difference in their current generation performances. Based on the experimental results, excellent stability, reliability, and low cost, TNA‐NF can be considered a promising and scalable MFC bioanode material. [ABSTRACT FROM AUTHOR]