7 Search Results

We report the synthesis and physical characterization of single-crystalline Ce3⁢MgBi5, a previously unexplored member of the Ce3⁢𝑀⁢𝑃⁢𝑛5 family. This compound crystallizes in the hexagonal 𝑃⁢63/𝑚⁢𝑐⁢𝑚 structure, featuring an anisotropic Ce sublattice composed of zigzag chains along the 𝑐 axis and a distorted kagome-like network in the basal plane. Magnetization measurements reveal antiferromagnetic order below 𝑇𝑁≈4.2K with strong magnetic anisotropy and multiple field-induced metamagnetic transitions for fields applied perpendicular to [001], leading to a dome-shaped 𝐻–𝑇 phase diagram. Electrical transport exhibits characteristic signatures of a Ce-based Kondo lattice, including broad resistivity maxima and pronounced field-dependent anomalies in the magnetoresistance and Hallmore » response that track the magnetic phase boundaries. Specific-heat measurements confirm the magnetic transition and show that the full R⁢ln⁡2 entropy expected for a Ce3+ Kramers doublet is recovered by 20 K, indicating an extended temperature range of magnetic fluctuations consistent with Kondo correlations. Our results establish Ce3⁢MgBi5 as a platform within the Ce3⁢𝑀⁢𝑃⁢𝑛5 family for exploring the interplay of geometric frustration, magnetic anisotropy, and Kondo-lattice physics under applied magnetic fields.« less

Single crystals of Ag⁢In⁢Cr4⁢S8 are grown by chemical vapor transport and crystallographic ordering of Ag/In that results in a breathing pyrochlore motif of Cr3+ is verified by x-ray and neutron diffraction. Long-range antiferromagnetic order is observed below a Néel temperature of 𝑇N ≈ 9.6 K. The magnetic properties are characterized using ac and dc magnetization, specific heat capacity, and single crystal neutron diffraction measurements. The specific heat data are characterized by a small lambda anomaly near 9.5 K and the estimated magnetic entropy reaches ≈ 13 of the expected value by 3⁢𝑇N, suggesting significant short-range order in the paramagnetic phase.more » Single crystal neutron diffraction evidences an incommensurate spin structure with propagation vector 𝒌 = (0,0,𝛿) and 𝛿 = 0.343 at 5 K. The minimal model that accounts for the data consists of ferromagnetic layers of Cr atoms, with magnetic moments lying in the plane of the layers and modulating in the perpendicular direction to form a helical structure propagating along 𝒌. This study represents a rare investigation of single crystals within the family of breathing pyrochlore materials.« less

Here, we report on the structural characterization and physical properties of Eu₂⁢InTe₅, a distorted square-net motif antiferromagnetic semiconductor. Single crystal x-ray diffraction measurements reveal a distortion of the Te square-net layers such that an orthorhombic supercell is necessary to accurately describe the structure. Magnetization, resistivity, and specific heat measurements confirm antiferromagnetic ordering at 𝑇_𝑁 = 7.3K. Anisotropy in magnetization data suggests the magnetic moments are oriented parallel to the 𝑐 axis. We observe an unconventional transverse magnetoresistance and Hall resistivity in the paramagnetic state (𝑇 ≤ 80K), indicating strong coupling between localized Eu²⁺ magnetic moments and conduction electrons. Resistivity andmore » Hall measurements indicate the material is a heavily doped semiconductor, with impurity states related to disorder. Our findings highlight a relatively unexplored Eu-based antiferromagnetic semiconductor with unconventional magnetotransport behavior.« less

The magnetic properties of EuAlSi, a compound comprising a honeycomb lattice of Al/Si atoms and a triangular lattice of Eu atoms, are presented. By means of single-crystal x-ray diffraction, we find that EuAlSi crystallizes in an AlB₂-type structure with space group 𝑃⁢6/mmm and unit cell parameters 𝑎 = 4.2229⁢ (10) ⁢Å and 𝑐 = 4.5268 ⁢(12)⁢ Å. Our magnetic measurements indicate that EuAlSi is a soft ferromagnetic material with 𝑇_Curie = 25.8 K. The susceptibility follows the Curie-Weiss law at high temperatures, which allowed us to determine the paramagnetic Curie temperature 𝜃_𝑃 = 36.2 ⁢(1) ⁢K and an effective magneticmore » moment 𝜇_eff = 8.07 ⁢(1)⁢ µ_𝐵/Eu. This value is in agreement with the theoretical value of 7.9 µ_𝐵 for Eu²⁺ free ion. Moreover, we have prepared the Eu_1−𝑥⁢Sr_𝑥⁢ AlSi solid solution, where the atoms in the triangular lattice were systematically exchanged, in order to study the evolution of the collective quantum properties from the ferromagnetic EuAlSi toward the superconducting SrAlSi. Across the Eu_1−𝑥⁢Sr_𝑥 AlSi solid solution, the unit cell parameters change linearly, following Vegard’s law, and making the system reliable for studying composition dependence of the interplay between the crystal structure and physical properties. As the Sr content increases, i.e., 𝑥 increases, we note a consistent reduction of 𝜇_eff and 𝑇_Curie. Long-range magnetic order in Eu_1−𝑥⁢Sr_𝑥⁢ AlSi persists up to 𝑥 = 0.95, whereas superconductivity is only observed for samples with 𝑥 > 0.97.« less

Here, we report an investigation of the magnetic, thermodynamic, and transport properties of single-crystalline Nd₃⁢ScBi₅ and Pr₃⁡ScBi₅. Both compounds crystallize in the hexagonal 𝑃⁢6₃/𝑚⁢𝑐⁢𝑚 space group that is common to related materials with rare-earth atoms that form twisted kagome nets. Nd₃⁢ScBi₅ undergoes two successive antiferromagnetic transitions, at 𝑇_𝑁=5.6K and 𝑇₂=4.7K. When a magnetic field is applied along [100], both 𝑇_𝑁 and 𝑇₂ are suppressed with increasing field, and multiple metamagnetic transitions are observed; in-plane anisotropy is demonstrated by a slight broadening and movement of the metamagnetic transitions when the field is applied along [110]. For H ∥ [001], 𝑇_𝑁 andmore » 𝑇₂ exhibit only a weak field dependence and metamagnetic transitions are not observed. The magnetoresistance and Hall effect respond strongly to the metamagnetic transitions and further motivate a detailed characterization of the magnetic structures under applied fields. Pr₃⁡ScBi₅, in contrast, undergoes a single antiferromagnetic transition at 𝑇_𝑁=5.3K and a single metamagnetic transition at higher fields. These findings place Nd₃⁢ScBi₅ and Pr₃⁡ScBi₅ as promising systems for exploring anisotropic magnetism and field-driven magnetic phase transitions in intermetallic compounds.« less

ErAl₃ can form in either a trigonal (α) or cubic (β) polymorph and this paper investigates the physical properties of these polymorphs through characterizations of single crystals grown in an aluminum flux. Here, we demonstrate that polymorph selection can be achieved based on the nominal composition of the crystal growth. Magnetic measurements confirm that both β-ErAl₃ and α-ErAl₃ order antiferromagnetically at low temperatures. β-ErAl₃ undergoes antiferromagnetic ordering at a Néel temperature T_N = 5.1 K, and the transition is suppressed continually with applied field. α-ErAl₃ displays more complex behavior, with successive magnetic transitions at T_N = 5.7 K and T₂more » = 4.6 K for zero field, where heat capacity and dilatometry measurements evidence that these transitions are second and first order, respectively. Under magnetic field, strong anisotropy is revealed in α-ErAl₃, with several steplike metamagnetic transitions observed below T₂ for H ∥ c. These transitions produce sequential magnetization plateaus near one-half of the apparent saturation magnetization. The electrical resistivity of α-ErAl₃ is strongly coupled to its magnetism. At T = 2 K, we observe a positive magnetoresistance reaching 60%, with distinct anomalies at the metamagnetic transitions. The results are summarized in H-T phase diagrams that demonstrate complex magnetic behavior for α-ErAl₃, suggesting an important role of competing interactions in this metallic system that possesses characteristics of Ising physics.« less

The synthesis, structural, magnetic, thermal, and transport properties are reported for polycrystalline PrI⁢r₃. At room temperature PrI⁢r₃ displays the rhombohedral space group R–3m and a PuNi₃-type structure. At around 70 K a phase transition to a monoclinic C⁢2/m structure is observed and continued cooling reveals temperature independent behavior of the unit cell volume. Further, PrI⁢r₃ undergoes a paramagnetic to ferromagnetic transition with T_c=7.5K. The temperature dependent magnetic susceptibility follows the Curie-Weiss law with a positive Curie-Weiss temperature, and an effective moment that is close to the theoretical effective moment for a free P⁢r⁺³ ion. Finally, the structural transition introduces furthermore » complexity into the behavior of PuNi₃-type materials and highlights the importance of temperature-dependent structural studies to complement physical property measurements in intermetallic compounds.« less