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We have studied the influence of external pressure up to 1 GPa on the magnetic transitions of the orthorhombic Haldane-spin chain compound Tb2BaNiO5 an exotic multiferroic material. This parent compound is known to undergo Neel ordering at TN1= 63 K and another magnetic transition at TN2= 25K at which ferroelectricity sets in, however, without any change in the magnetic symmetry, but with only a sharp change in the canting angle of Tb 4f and Ni 3d magnetic moments. There is a subtle difference in the antiferromagnetic state above and below TN2, which is supported by the fact that there is a metamagnetic transition below TN2only (for 5 K, at about 60 kOe). We report here that, with the application of external pressure, there is an upward shift of TN1, while TN2 shifts towards lower temperatures. It is interesting that the two magnetic transitions in the same compound behave differently under pressure and the opposite behavior at TN2 is attributed to local distortion leading to ferroelectricity. The results are augmented by temperature dependent x-ray diffraction and positive chemical pressure studies. The chemical pressure caused by the isoelectronic doping at Ba site by Sr reduces both the transition temperatures. Clearly, the external pressure favors antiferromagnetic coupling (that is, leading to TN1 enhancement), whereas the chemical pressure reduces TN1, suggesting important role of the changes in local hybridization induced by doping on magnetism in this material.
We report the magnetic field dependent dc magnetization and the pressure-dependent (pmax ~ 16 kbar) ac susceptibilities Xp(T) on both powder and bulk multiferroic BiMnO3 samples, synthesized in different batches under high pressure. A clear ferromagn
In order to clarify the mechanism associated with pressure/magnetic-field-induced giant ferroelectric polarization in TbMnO3, this work investigated changes in magnetic ordering brought about by variations in temperature, magnetic field, and pressure
A quantum critical point is approached by applying pressure in a number of magnetic metals. The observed dependence of Tc on pressure necessarily means that the magnetic energy is coupled to the lattice. A first order phase transition occurs if this
Pressure induced isostructural insulator to metal transition for SmS is characterised by the presence of an intermediate valence state at higher pressure which cannot be captured by the density functional theory. As a direct outcome of including the
We report a magnetic x-ray scattering study of the field-induced multiferroic GdFe3(BO3)4. Resonant x-ray magnetic scattering at the Gd LII,III edges indicates that the Gd moments order at TN ~ 37 K. The magnetic structure is incommensurate below TN,