We report on the electric-field tuning of a magnetic phase transition temperature (TL) in multiferroic Ni3V2O8 thin films. The simultaneous magnetic and ferroelectric transition in Ni3V2O8 exhibits a clear dielectric anomaly; we monitored TL under applied electric and magnetic fields using dielectric measurements. The transition temperature increases by 0.2 K±0.05 K when the sample is biased ap...

The influence of magnetic field on the dielectric properties of several Mn1-x(Mg,Zn)xWO4 multiferroic ceramics is investigated, and confirms an additional phase transition below the ferroelectric Curie temperature previously detected in this system in zero magnetic field. In highly doped samples an original plateau of the capacitance is observed between T2 and this additional transition. Pyroel...

We study a nonequilibrium Ising model that stochastically evolves under the simultaneous operation of several spin-flip mechanisms. In other words, the local magnetic fields change sign randomly with time due to competing kinetics. This dynamics models a fast and random diffusion of disorder that takes place in dilute metallic alloys when magnetic ions diffuse. We perform Monte Carlo simulation...

Magnetocaloric effect is the phenomenon that temperature change of a magnetic material is induced by application of a magnetic field. This effect can be applied to environmentally-benign magnetic refrigeration technology. Here we show a key role of magnetic-field-induced structural instability in enhancing the magnetocaloric effect for MnCo(1-x)Zn(x)Ge alloys (x = 0-0.05). The increase in x rap...

By means of high-resolution ultrasonic velocity measurements, as a function of temperature and magnetic field, the nature of the different low temperatures magnetic phase transitions observed for the quasi-one-dimensional compound CsNiCl3 is established. Special attention has been devoted to the field-induced 120 degrees phase transition above the multicritical point in the H-T phase diagram wh...

Thermal expansion and magnetostriction, the strain responses of a material to temperature and a magnetic field, especially properties at low temperature, are extremely useful to study electronic and phononic properties, phase transitions, quantum criticality, and other interesting phenomena in cryogenic engineering and materials science. However, traditional dilatometers cannot provide magnetic...

We have investigated the electronic, magnetic, and optical properties of two Fe-based superconductors and related parent compounds via three powerful techniques: scanning tunneling microscopy/spectroscopy (STM/S), high-temperature vibrating sample magnetometry, and optical transmission spectroscopy (OTS). Below the superconducting transition temperature Tc ∼ 48 K, the STM/S of polycrystalline N...