arXiv subjects

R. Daou

Publications and source records attributed to R. Daou.

21 records · Page 2Linked to original sources

arXiv2006

Negative magnetocaloric effect from highly sensitive metamagnetism in CoMnSi_{1-x}Ge_{x}

We report a novel negative magnetocaloric effect in CoMnSi_{1-x}Ge_{x} arising from a metamagnetic magnetoelastic transition. The effect is of relevance to magnetic refrigeration over a wide range of temperature, including room temperature. In addition we report a very high shift in the metamagnetic transition temperature with applied magnetic field. This is driven by competition between antiferromagnetic and ferromagnetic order which can be readily tuned by applied pressure and compositional changes.

cond-mat.str-el↗

arXiv2005

Continuous Evolution of the Fermi Surface of CeRu2Si2 across the Metamagnetic Transition

We present new, high resolution Hall effect and magnetoresistance measurements across the metamagnetic transition in the heavy fermion compound CeRu2Si2. The results force us to rethink the notion that the transition is accompanied by an abrupt f-electron localisation. Instead, we explain our data assuming a continuous change of the Fermi surface. We also point out ambiguities in the interpretation of dHvA data and give a possible solution to the problem of the "missing mass".

cond-mat.str-el↗

arXiv2002

Critical end-point and metamagnetic quantum criticality in Sr3Ru2O7

We report a metamagnetic critical point at (B*,T*)=(5.1T,1.1K) for magnetic fields applied perpendicular to the (tetragonal) c-axis of Sr3Ru2O7. First-order behaviour well below T* indicates that (B*,T*) marks a critical end-point that terminates a line of first-order metamagnetic transitions. The absence of first-order behaviour in the metamagnetic transition with B||c confirms that the non-Fermi liquid behaviour for B||c is underpinned by a metamagnetic quantum critical end-point for which T*->0. Scaling behaviour of the resistivity under hydrostatic pressure yields the surprising result that although B* increases rapidly with pressure, T* has only a weak pressure dependence.

cond-mat.str-el↗