Showing papers on "Metamagnetism published in 2021"
TL;DR: In this paper, the phase diagram of UTe2 under two magnetic field directions: the hard magnetization axis b, and a direction titled by ≃25-30° from b in the (b,c) plane.
Abstract: Superconductivity induced by a magnetic field near metamagnetism is a striking manifestation of magnetically-mediated superconducting pairing. After being observed in itinerant ferromagnets, this phenomenon was recently reported in the orthorhombic paramagnet UTe2. Here we explore the phase diagram of UTe2 under two magnetic-field directions: the hard magnetization axis b, and a direction titled by ≃25-30° from b in the (b,c) plane. Zero-resistivity measurements confirm that superconductivity is established beyond the metamagnetic field Hm in the tilted-field direction. While superconductivity is locked exactly at fields either smaller (for H | | b), or larger (for H tilted by ≃27° from b to c), than Hm, the variations of the Fermi-liquid coefficient in the electrical resistivity and of the residual resistivity are similar for the two field directions. The resemblance of the normal states for the two field directions puts constraints for theoretical models of superconductivity and implies that some subtle ingredients must be in play. In a magnetic field, superconductivity can be induced or reinforced near a metamagnetic transition, where ferromagnetic fluctuations are suspected to mediate the pairing strength of the Cooper pairs. Here, the authors investigate the superconductor UTe2 and report on the variation in the superconducting properties as the magnetic field is applied along two particular crystallographic axes and their relation to metamagnetism.
31 citations
TL;DR: By gradually substituting Al for In in Gd2In1−xAlx (0.4 −1) system, the hexagonal structure is gradually evolved into orthorhombic one for x ≥ 0.7 as discussed by the authors.
12 citations
TL;DR: In this article, an unconventional nonhysteretic metamagnetic phase transition is observed at the critical composition of x = 0.2 in Er2In1-xAlx (0,≤,x, ≥ 0.4) system.
11 citations
TL;DR: In this paper, a quasi-two-dimensional antiferromagnets with a kagome-type lattice was synthesized with the structure of the francisite mineral, Cu3Bi(SeO3)2O2Cl.
Abstract: The synthesis of new geometrically frustrated layered systems has fueled experimental work and progress in building models of low-dimensional magnetism. Compounds with the structure of the francisite mineral, Cu3Bi(SeO3)2O2Cl, are quasi-two-dimensional antiferromagnets with a kagome-type lattice. With the dominant ferromagnetic interaction in the layer and a weak interlayer antiferromagnetic bond, the main noncollinear state of francisite is easily destroyed by an external magnetic field, which opens the possibility of reversible switching between states with the minimum and maximum possible magnetization. In the region of metamagnetic transition, multiferroelectric effects and broadband absorption of electromagnetic waves are observed. The implantation of rare-earth ions R into the Bi position is accompanied by spin-reorientation phase transitions in Cu3 R(SeO3)2 O2 X compounds, where X = Cl, Br.
7 citations
TL;DR: In this article, the authors used Monte Carlo simulations and electronic structure models to calculate the ground state magnetic phase diagram as well as topological and optical properties for few layer films with thickness up to six septuple layers.
Abstract: MnBi$_2$Te$_4$ (MBT) is a promising antiferromagnetic topological insulator whose films provide access to novel and technologically important topological phases, including quantum anomalous Hall states and axion insulators. MBT device behavior is expected to be sensitive to the various collinear and non-collinear magnetic phases that are accessible in applied magnetic fields. Here, we use classical Monte Carlo simulations and electronic structure models to calculate the ground state magnetic phase diagram as well as topological and optical properties for few layer films with thicknesses up to six septuple layers. Using magnetic interaction parameters appropriate for MBT, we find that it is possible to prepare a variety of different magnetic stacking sequences, some of which have sufficient symmetry to disallow non-reciprocal optical response and Hall transport coefficients. Other stacking arrangements do yield large Faraday and Kerr signals, even when the ground state Chern number vanishes.
7 citations
TL;DR: In this article, the double perovskite compound Tb2CoMnO6 has been investigated using x-ray absorption spectroscopy (XAS), Raman Spectroscopy, magnetic measurements and ab initioband structure calculations.
Abstract: The double perovskite compound Tb2CoMnO6has been investigated using x-ray absorption spectroscopy (XAS), Raman spectroscopy, magnetic measurements andab initioband structure calculations. It is observed that both anti-ferromagnetic (AFM) and ferromagnetic (FM) phase coexist in this material. The presence of anti-site disorder (ASD) has been established from the analysis of neutron diffraction data. Moreover, a prominent metamagnetic transition is observed in theM(H) behavior that has been explained with the drastic reorientation of the pinned domain which are aligned antiparallel by the antiphase boundaries (APBs) at zero field. The ASD further gives rise to spin frustration at low temperature which leads to the re-entrant cluster glass ∼33 K. The coupling between phononic degree of freedom and spin in the system has also been demonstrated. It is observed that the theoretical calculation is consistent with that of the experimentally observed behavior.
6 citations
TL;DR: In this paper, the magnetic, magneto-caloric, electronic structure, and optical properties of rare earth intermetallics RRhSi (R=Tb, Dy, Ho) were reported.
6 citations
TL;DR: The (NH4)2[ReF6] (1) salt was studied by X-ray diffraction, Raman spectroscopy, theoretical calculations, and magnetic measurements.
Abstract: The (NH4)2[ReF6] (1) salt was studied by X-ray diffraction, Raman spectroscopy, theoretical calculations, and magnetic measurements 1 crystallizes in the trigonal space group Pm1 (Re–F = 1958(5) A) In the Raman spectrum of 1, splitting of the observed peaks was observed and correlated to the valence frequencies of vibration of the [ReF6]2− anion The study of the magnetic properties of 1, through DC and AC magnetic susceptibility measurements, reveals the coexistence of metamagnetism and slow relaxation of magnetization at low temperature, which is unusual in the molecular systems based on the paramagnetic 5d metal ions reported so far
6 citations
TL;DR: In this article, two new compounds of general formula [M(N3)2(dmbpy] have been synthesized and characterized structurally and magnetically, in which dmbpy = 5,5′-dimethyl-2,2′-bipyridine, and M = Mn(II) or Co(II), have been solvothermally synthesized.
Abstract: Two new compounds of general formula [M(N3)2(dmbpy)] in which dmbpy = 5,5′-dimethyl-2,2′-bipyridine, and M = Mn(II) or Co(II), have been solvothermally synthesized and characterized structurally and magnetically The structures consist of zig-zag polymeric chains with alternating bis-µ(azide-N1)2M and bis-µ(azide-N1,N3)2M units in which the cis-octahedrally based coordination geometry is completed by the N,N’-chelating ligand dmbpy The molecular structures are basically the same for each metal The Mn(II) compound has a slightly different packing mode compared to the Co(II) compound, resulting from their different space groups Interestingly, relatively weak interchain interactions are present in both compounds and this originates from π–π stacking between the dmbpy rings The magnetic properties of both compounds have been investigated down to 2 K The measurements indicate that the manganese compound shows spin-canted antiferromagnetic ordering with a Neel temperature of TN = 34 K and further, a field-induced magnetic transition of metamagnetism at temperatures below the TN This finding affords the first example of an 1D Mn(II) compound with alternating double end-on (EO) and double end-to-end (EE) azido-bridged ligands, showing the coexistence of spin canting and metamagnetism The cobalt compound shows a weak ferromagnetism resulting from a spin-canted antiferromagnetism and long-range magnetic ordering with a critical temperature, TC = 162 K
5 citations
5 citations
TL;DR: In this paper, a cubic quadruple perovskite oxide CeMn3Cr4O12 has been synthesized under high pressure and high-temperature conditions of 8 GPa and 1273 K.
Abstract: A cubic quadruple perovskite oxide CeMn3Cr4O12 has been synthesized under high-pressure and high-temperature conditions of 8 GPa and 1273 K. The X-ray absorption spectroscopy reveals that the Ce ions are in a trivalent state, as represented by the ionic model of Ce3+Mn3+3Cr3+4O12. The magnetic study demonstrates three independent antiferromagnetic transitions attributed to Ce (∼10 K), Mn (46 K), and Cr (133 K) ions. Furthermore, a magnetic field-induced antiferromagnetic-to-ferromagnetic (metamagnetic) transition of Ce3+ 4f moments is observed at low temperatures below 20 K, exhibiting a rare example of metamagnetism in the Ce3+-oxides. This finding represents that the 3d-electron magnetic sublattices play a role in the metamagnetism of 4f-electron magnetic moments, demonstrating a new aspect of the 3d-4f complex electron systems.
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TL;DR: In this article, the Coulomb Hubbard interaction U applied to the Ru 4d states has dramatic effects on the Fermi surface, revealing the role of Coulomb interactions and correlated many-body physics.
Abstract: We report electronic band structure calculations for Sr$_{4}$Ru$_{3}$O$_{10}$ that displays both ferromagnetic and metamagnetic behavior. The density functional calculations find the ground state to be ferromagnetic in agreement with the experiment and we find that the inclusion of Coulomb Hubbard interaction U applied to the Ru 4d states has dramatic effects on the Fermi surface, which reveal the role of Coulomb interactions and correlated many-body physics. The minority spin bands are mainly empty with Fermi surfaces in the outer areas of the Brillouin zone away from the $\Gamma$ point with bands that disperse steeply upward. The majority spin bands are full or nearly fully occupied and form narrow bands near the Fermi energy around the $\Gamma$ point, which could be the electronic origin of the metamagnetism. The results are in qualitative agreement with recent angle resolved photoemission spectroscopy (ARPES) experiments and show the need for a combined theoretical study and experimental ARPES investigation with better energy resolution to reveal the nature of the narrow bands close to the Fermi-level, which is critical for understanding the exotic magnetic properties observed in this material.
TL;DR: In this article, the magnetic properties of EuCd2As2 single crystals were investigated and the authors showed that magnetic moments lying in the ab plane are more sensitive to the in-plane magnetic moments than the out-of-plane field.
TL;DR: It is argued that the metamagnetic transition of UPt$_3$, which occurs at an applied field $\mu_\circ H_M \sim 20$ T, coincides with a Lifshitz transition at which an open orbit on the band 2 hole-like Fermi surface becomes closed for one spin direction.
Abstract: Comparing quantum oscillation measurements, dc magnetoresistance measurements, and Fermi surfaces obtained from LDA calculations, we argue that the metamagnetic transition of UPt3, which occurs at an applied field μ ◦ H M ∼ 20 T, coincides with a Lifshitz transition at which an open orbit on the band 2 hole-like Fermi surface becomes closed for one spin direction. At low field, proximity of the Fermi energy to this particular van Hove singularity may have implications for the superconducting pairing potential of UPt3. In our picture the magnetization comes from non-linear spin-splitting of the heavy fermion bands. In support of this, we show that the non-linear field dependence of a particular quantum oscillation frequency can be fitted by assuming that the corresponding extremal Fermi surface area is proportional to the magnetization. In addition, below H M , we find in our LDA calculations a new, non-central orbit on band 1, whose non-linear behaviour explains a field-dependent frequency recently observed in magnetoacoustic quantum oscillation measurements.
TL;DR: In this paper, the ground state magnetic phase diagram as well as topological and optical properties for few-layer films with up to six septuple layers were calculated using classical Monte Carlo simulations and electronic structure models.
Abstract: ${\mathrm{MnBi}}_{2}{\mathrm{Te}}_{4}$ (MBT) materials are a promising class of antiferromagnetic topological insulators whose films provide access to novel and technologically important topological phases, including quantum anomalous Hall states and axion insulators. MBT device behavior is expected to be sensitive to the various collinear and noncollinear magnetic phases that are accessible in applied magnetic fields. Here, we use classical Monte Carlo simulations and electronic structure models to calculate the ground state magnetic phase diagram as well as topological and optical properties for few-layer films with up to six septuple layers. Using magnetic interaction parameters appropriate for MBT, we find that it is possible to prepare a variety of different magnetic stacking sequences, some of which have sufficient symmetry to disallow nonreciprocal optical response and Hall transport coefficients. Other stacking arrangements do yield large Faraday and Kerr signals, even when the ground state Chern number vanishes.
TL;DR: In this article, the crystal structure, magnetic and thermal properties of EuPd2Sn4 stannide were reported, and a divalent state of the rare earth element was determined together with an antiferromagnetic (AFM) order at 11 K.
Abstract: We report on crystal structure, magnetic and thermal physical properties of EuPd2Sn4 stannide. From the magnetic susceptibility measurements a divalent state of Eu rare earth element was determined together with an antiferromagnetic (AFM) order at 11 K. By applying magnetic field, the magnetic behavior variation reveals a complex magnetic structure. Above a critical field Bc a ferromagnetic (FM)-like character starts to prevail. AFM and FM regimes are separated by a metamagnetic region. Heat capacity measurements confirm this behavior.
TL;DR: An olivine-type orthothiophospate LiMnPS4 has been synthesized for the first time through a building block approach by reacting preformed ternary lithium thiophase with MnCl2.