Prabhat Mandal

Large magnetocaloric effect in Sm0.52Sr0.48MnO3 in low magnetic field

This letter reports on the magnetocaloric properties of Sm0.52Sr0.48MnO3 single crystal. A magnetic field of only 1T yields a change in the magnetic entropy by 5.9J∕(kgK) at TC (=124K), which is higher than those observed in several other perovskite manganites and rare earth alloys of comparable TC. This change originates from a sharp magnetization jump, associated with a first-order metamagnetic transition. Such a large change in entropy at a low magnetic field makes this material useful for magnetic refrigeration.

Large nonsaturating magnetoresistance and signature of nondegenerate Dirac nodes in ZrSiS

Significance Topological semimetals provide the opportunity to explore the fundamental physics of relativistic particles and offer the possibility of technological applications. However, finding robust systems with a sufficiently large range of linearly dispersing bands remains elusive. Recently discovered Dirac semimetal ZrSiS hosts multiple Dirac cones with the largest reported energy range of linear band dispersion (∼2 eV). In this work, we report transport measurements on ZrSiS, exploring extreme and anisotropic magnetoresistance with distinct quantum oscillations, enabling us to quantitatively analyze the Fermi surface properties. We have also observed the unique signature of chiral anomaly in longitudinal magnetoresistance. Our work comprehensively confirms the recent theoretical and angle-resolved photoemission spectroscopy results on ZrSiS and suggests a large family of materials as potential topological semimetals. Whereas the discovery of Dirac- and Weyl-type excitations in electronic systems is a major breakthrough in recent condensed matter physics, finding appropriate materials for fundamental physics and technological applications is an experimental challenge. In all of the reported materials, linear dispersion survives only up to a few hundred millielectronvolts from the Dirac or Weyl nodes. On the other hand, real materials are subject to uncontrolled doping during preparation and thermal effect near room temperature can hinder the rich physics. In ZrSiS, angle-resolved photoemission spectroscopy measurements have shown an unusually robust linear dispersion (up to ∼2 eV) with multiple nondegenerate Dirac nodes. In this context, we present the magnetotransport study on ZrSiS crystal, which represents a large family of materials (WHM with W = Zr, Hf; H = Si, Ge, Sn; M = O, S, Se, Te) with identical band topology. Along with extremely large and nonsaturating magnetoresistance (MR), ∼1.4 × 105% at 2 K and 9 T, it shows strong anisotropy, depending on the direction of the magnetic field. Quantum oscillation and Hall effect measurements have revealed large hole and small electron Fermi pockets. A nontrivial π Berry phase confirms the Dirac fermionic nature for both types of charge carriers. The long-sought relativistic phenomenon of massless Dirac fermions, known as the Adler–Bell–Jackiw chiral anomaly, has also been observed.

Modification of the spin state in Sm0.52Sr0.48MnO3 by external magnetic field

The effect of applied magnetic field (H) on the magnetic properties of Sm0.52Sr0.48MnO3 single crystal in the paramagnetic (PM) state has been investigated. We observe a field induced steplike jump in magnetization (M) above TC (110K). The temperature and magnetic field dependence of susceptibility reveal that the PM phase of this system is quite complicated due to the coexistence of ferromagnetic (FM) and antiferromagnetic (AFM) interactions. The nature of magnetic interaction changes abruptly from AFM to FM at around 3.5T, above which M ceases the steplike jump.

Hydrostatic pressure effect on archetypal Sm0.52Sr0.48MnO3 single crystal

The effect of hydrostatic pressure (P) on the c-axis electrical resistivity (rho(c)) and ferromagnetic (FM) transition temperature (T(C)) Of Sm(0.52)Sr(0.48)MnO(3) single crystal has been investigated. At P=O, the strong hysteretic nature of metal-insulator transition (MIT) and the abrupt decrease of pc by several orders just below T(C) suggest that the FM transition is discontinuous in nature. The application of pressure strongly decreases rho(c), shifts MIT to higher temperature at the rate of 19 K/GPa, and suppresses the hysteresis width. The nature of the FM phase transition would change from discontinuous to continuous at around P=2.5 GPa. 0 2008 American Institute of Physics.

Probing the Fermi surface of three-dimensional Dirac semimetalCd3As2through the de Haas–van Alphen technique

We have observed Shubnikov-de Haas and de Haas-van Alphen effect in the single crystals of three dimensional Dirac semimetal Cd

Coexistence of topological Dirac fermions in the surface and three-dimensional Dirac cone state in the bulk of ZrTe

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Determination of intrinsic ferroelectric polarization in lossy improper ferroelectric systems

upto 50 K, traceable at field as low as 2 T and 1 T, respectively. The values of Fermi wave vector, Fermi velocity, and effective cyclotron mass of charge carrier, calculated from both the techniques, are close to each other and match well with the earlier reports. However, the de Haas-van Alphen effect clearly reflects the existence of two different Fermi surface cross-sections along certain direction and a non-trivial Berrys phase which is the signature of 3D Dirac Fermion in Cd

Giant low-field magnetocaloric effect in single-crystalline EuTi0.85Nb0.15O3

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