| Title: |
Competing Magnetism in Layered Mixed Transition Metal Chalcogenides KCo 2– x Ni x Se 2 , KCo 2– x Ni x S 2 , and CsCo 2– x Ni x Se 2 |
| Authors: |
Ludmila Taskesen; Robert D. Smyth; Lemuel E. Crentsil; James I. Murrell; Emmanuelle Suard; Pascal Manuel; Simon J. Clarke |
| Publication Year: |
2025 |
| Collection: |
The University of Auckland: Figshare |
| Subject Terms: |
Medicine; Evolutionary Biology; Ecology; Hematology; Environmental Sciences not elsewhere classified; Astronomical and Space Sciences not elsewhere classified; Biological Sciences not elsewhere classified; Chemical Sciences not elsewhere classified; Physical Sciences not elsewhere classified; powder neutron diffraction; per cobalt ion; nickel substitution enhances; nickel content causes; measurable bragg peaks; high co contents; antiferromagnetic interactions along; ∼ 90 k; type antiferromagnetic order; probed using magnetometry; per transition metal; magnetic ordering temperature; applied magnetic field; range ordering exhibits; increasing nickel substitution; analogous sulfide series; b |
| Description: |
Layered transition metal chalcogenides are a versatile class of compounds that exhibit exotic physical phenomena, including superconductivity, thermoelectric properties and magnetic properties. The magnetic properties of ThCr 2 Si 2 -type solid solutions KCo 2– x Ni x Ch 2 ( Ch = S, Se; 0 ≤ x ≤ 2) with metallic properties were probed using magnetometry and powder neutron diffraction (PND). KCo 2 Se 2 is ferromagnetic below ∼90 K and powder neutron diffraction (PND) showed evidence for long-range ferromagnetic order with localized moments of 0.6 μ B per cobalt ion. With increasing nickel substitution, the system starts to order antiferromagnetically at x = 0.5. In these cases, PND experiments showed long-range A-type antiferromagnetic order with localized moments of around 1 μ B per transition metal at 5 K. The Néel temperature ( T N ) for three-dimensional long-range ordering exhibits a maximum at x = 1, suggesting that nickel substitution enhances the antiferromagnetic interactions along the stacking direction. Higher nickel content suppresses the magnetic ordering temperature, and KCo 0.5 Ni 1.5 Se 2 shows no magnetic long-range order with a lack of measurable Bragg peaks by PND (although a magnetic transition is evident by magnetometry), and further increasing the nickel content causes the system to become paramagnetic in the region 1.6 ≤ x ≤ 2. Our results show that increasing the electron count in the KCo 2– x Ni x Se 2 series has a dramatic effect on the physical properties. The analogous sulfide series - KCo 2– x Ni x S 2 shows similar behavior, and the series CsCo 2– x Ni x Se 2 , containing a larger alkali metal ion, is comparable apart from the lack of a ferromagnetic region at high Co contents in the absence of an applied magnetic field. |
| Document Type: |
article in journal/newspaper |
| Language: |
unknown |
| Relation: |
https://figshare.com/articles/journal_contribution/Competing_Magnetism_in_Layered_Mixed_Transition_Metal_Chalcogenides_KCo_sub_2_i_x_i_sub_Ni_sub_i_x_i_sub_Se_sub_2_sub_KCo_sub_2_i_x_i_sub_Ni_sub_i_x_i_sub_S_sub_2_sub_and_CsCo_sub_2_i_x_i_sub_Ni_sub_i_x_i_sub_Se_sub_2_sub_/29540796 |
| DOI: |
10.1021/acs.chemmater.5c00996.s001 |
| Availability: |
https://doi.org/10.1021/acs.chemmater.5c00996.s001; https://figshare.com/articles/journal_contribution/Competing_Magnetism_in_Layered_Mixed_Transition_Metal_Chalcogenides_KCo_sub_2_i_x_i_sub_Ni_sub_i_x_i_sub_Se_sub_2_sub_KCo_sub_2_i_x_i_sub_Ni_sub_i_x_i_sub_S_sub_2_sub_and_CsCo_sub_2_i_x_i_sub_Ni_sub_i_x_i_sub_Se_sub_2_sub_/29540796 |
| Rights: |
CC BY-NC 4.0 |
| Accession Number: |
edsbas.38B00D63 |
| Database: |
BASE |