Attention:The NSF Public Access Repository (PAR) system and access will be unavailable from 11:00 PM ET on Thursday, October 15th until 12:00 AM ET on Friday, October 16th due to maintenance. We apologize for the inconvenience.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: Tuning Magnetic and Transport Properties in Quasi-2D (Mn1−xNix)2P2S6 Single Crystals
We report an optimized chemical vapor transport method to grow single crystals of (Mn1−xNix)2P2S6 where x = 0, 0.3, 0.5, 0.7, and 1. Single crystals up to 4 mm × 3 mm × 200 μm were obtained by this method. As-grown crystals are characterized by means of scanning electron microscopy and powder X-ray diffraction measurements. The structural characterization shows that all crystals crystallize in monoclinic symmetry with the space group C2/m (No. 12). We have further investigated the magnetic properties of this series of single crystals. The magnetic measurements of the all as-grown single crystals show long-range antiferromagnetic order along all principal crystallographic axes. Overall, the Néel temperature TN is non-monotonous; with increasing Ni2+ doping, the temperature of the antiferromagnetic phase transition first decreases from 80 K for pristine Mn2P2S6 (x = 0) up to x = 0.5 and then increases again to 155 K for pure Ni2P2S6 (x = 1). The magnetic anisotropy switches from out-of-plane to in-plane as a function of composition in (Mn1−xNix)2P2S6 series. Transport studies under hydrostatic pressure on the parent compound Mn2P2S6 evidence an insulator-metal transition at an applied critical pressure of ~22 GPa.  more » « less
Award ID(s):
1903888
PAR ID:
10276997
Author(s) / Creator(s):
; ; ; ; ; ;
Date Published:
Journal Name:
Electronic Materials
Volume:
2
Issue:
3
ISSN:
2673-3978
Page Range / eLocation ID:
284 to 298
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; ; ; ; (, Journal of Applied Physics)
    The effects of doping, hydrostatic pressure, and thermal quenching on the phase transitions and magnetocaloric properties of the Mn1−xCoxNiGe system have been investigated. Cobalt doping on the Mn site shifted the martensitic structural transition toward lower temperature until it was ultimately absent, leaving only a magnetic transition from a ferromagnetic (FM) to a paramagnetic (PM) state in the high-temperature hexagonal phase. Co-occurrence of the magnetic and structural transitions to form a first-order magnetostructural transition (MST) from the FM orthorhombic to the PM hexagonal phase was observed in samples with 0.05 < x < 0.20. An additional antiferromagnetic–ferromagnetic-like transition was observed in the martensite phase for 0.05 < x < 0.10, which gradually vanished with increasing Co concentration (x > 0.10) or magnetic field (H > 0.5 T). The application of external hydrostatic pressure shifted the structural transition to lower temperature until an MST was formed in samples with x = 0.03 and 0.05, inducing large magnetic entropy changes up to −80.3 J kg−1 K−1 (x = 0.03) for a 7-T field change under 10.6-kbar pressure. Similar to the effects of the application of hydrostatic pressure, an MST was formed near room temperature in the sample with x = 0.03 by annealing at high temperature (1200 °C) followed by quenching, resulting in a large magnetic entropy change of −56.2 J kg−1 K−1. These experimental results show that the application of pressure and thermal quenching, in addition to compositional variations, are effective methods to create magnetostructural transitions in the MnNiGe system, resulting in large magnetocaloric effects. 
    more » « less
  2. ; ; ; ; ; ; ; ; ; ; et al (, Crystals)
    Single crystals of the perovskite nickelate NdNiO3 with dimensions of up to 50 μm on edge have been successfully grown using the flux method at a temperature of 400 °C and oxygen pressure of 200 bar. The crystals were investigated by a combination of techniques, including high-resolution synchrotron X-ray single-crystal and powder diffraction and physical property measurements such as magnetic susceptibility and resistivity. Resistivity measurements revealed a metal-insulator transition (MIT) at TMIT~180 K with apparent thermal hysteresis; however, no superlattice peaks or peak splitting below TMIT, which corresponds to a structural transition from Pbnm to P21/n, was observed. The successful growth of NdNiO3 crystals at relatively low temperatures and oxygen pressure provides an alternative approach for preparing single crystals of interesting perovskites such as RNiO3 (R = Sm-Lu) and parent phases of superconducting square planar nickelates. 
    more » « less
  3. ; ; ; ; (, ACS Applied Materials & Interfaces)
    Two-dimensional (2D) magnetic materials provide a fertile platform for exploring low-dimensional magnetism and anisotropy-driven magnetic ordering, yet achieving continuous and controllable tuning of magnetic anisotropy remains a significant challenge. Here, we report a systematic chemical strategy to modulate magnetic anisotropy in a family of quasi-2D-layered hybrid organic–inorganic perovskites, (PEA)2Mn1–xCuxCl4 (0 ≤ x ≤ 1). Single crystals spanning the full compositional range were grown via a slow evaporation method, yielding phase-pure materials that exhibit continuous solid-solution behavior without phase segregation. Structural characterization confirms a common layered framework across all compositions, with gradual lattice evolution upon Mn2+/Cu2+ substitution. Comprehensive DC and AC magnetization measurements performed along orthogonal crystallographic directions reveal a progressive transformation of the magnetic ground state from Ising-type antiferromagnetism in (PEA)2MnCl4 to XY-type ferromagnetism in (PEA)2CuCl4. Intermediate compositions display coexistence of antiferromagnetic and ferromagnetic interactions, accompanied by a continuous crossover from easy-axis to easy-plane magnetic anisotropy. Field-dependent measurements further demonstrate a coherent evolution of spin-flop behavior, hysteresis, and saturation magnetization across the series. These results establish chemical substitution as an effective and versatile route for engineering magnetic anisotropy in hybrid perovskites, positioning transition-metal-based 2D HOIPs as a chemically programmable platform for tunable low-dimensional magnetism and future spintronic applications. 
    more » « less
  4. ; ; ; ; ; ; (, Crystals)
    Single crystals of a new transition metal adelite-descloizite-type structure were synthesized using a high temperature (580 °C) high-pressure hydrothermal technique. Single crystal X-ray diffraction and energy dispersive X-ray analysis (EDX) were used to investigate the structure and elemental composition, respectively. SrNi(VO4)(OH) crystallizes in an acentric orthorhombic crystal system in the space group P212121 (no. 19); Z = 4, a = 5.9952(4) Å, b = 7.5844(4) Å, c = 9.2240(5) Å. The structure is comprised of a Ni–O–V framework where Sr2+ ions reside inside the channels. Single-crystal magnetic measurements display a significant anisotropy in both temperature- and field-dependent data. The temperature dependent magnetic measurement shows antiferromagnetic behavior at TN~8 K. Overall, the magnetic properties indicate the presence of competing antiferromagnetic and ferromagnetic interactions of SrNi(VO4)(OH). 
    more » « less
  5. ; ; ; ; ; ; ; (, Journal of Physics: Condensed Matter)
    Abstract We report high-pressure x-ray diffraction and electrical resistance measurements on Sr(Co0.88Ni0.12)2P2, an itinerant antiferromagnet with the highest Néel temperature (TN= 36 K) among Sr(Co1−xNix)2P2series. Room-temperature diffraction data reveal a pressure-induced transition from an uncollapsed tetragonal (ucT) to a collapsed tetragonal (cT) structure, beginning near 8.4 GPa and completing before 12.4 GPa. This transition is characterized by an expansion of the in-plane a-lattice parameter and a contraction in the c-lattice parameter, resulting in a reduction of the axial ratio c/a. Resistance measurements show a low-pressure anomaly near 38 K, consistent with the reported antiferromagnetic transition. As the room temperature value of the applied pressure exceeds 8 GPa, signs of a partial cT transition appear on cooling with the full cT transition occurring for pressures exceeding 10 GPa. Associated with the cT phase is a much higher temperature ferromagnetic transition with Curie temperature reaching ∼ 190 K before slowly decreasing for higher applied pressures. These results demonstrate strong coupling between the lattice collapse and magnetic behavior in Sr(Co0.88Ni0.12)2P2. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Text Encoded Conversion
  • XML
  • Save / Share this Record
  • Send to Email