High-pressure synthesis and structural, transport, and magnetic properties of rutile-type C r2Re O6 and CrRe O4
Abstract
We have synthesized the cation ordered rutile-type C r2Re O6 and CrRe O4 under high-pressure and high-temperature conditions and performed detailed characterizations on their structural, transport, and magnetic properties via x-ray and neutron powder diffraction, resistivity, magnetic susceptibility, and specific heat measurements. C r2Re O6 crystallizes in the inverse trirutile structure with lattice parameters a =b =4.552 21 (5 )Å and c =8.8934 (1 )Å in the space group P 42/m n m . It undergoes a second-order antiferromagnetic transition at TN≈67 K with the magnetic structure described by the propagation vector k =[0.5 ,0 ,0.5 ] . For CrRe O4 , it adopts a monoclinically distorted rutile-like structure with unit-cell parameters a =9.3393 (2 )Å , b =5.6869 (1 )Å , c =4.6243 (1 )Å , and β =92.043 (8) ∘ in the space group C 2 /m . It also exhibits an antiferromagnetic order at TN=98 K with the magnetic structure described by the propagation vector k =[1 ,0 ,0.5 ] . Interestingly, a large paramagnetic Weiss temperature of θCW=-478 K is evidenced from the Curie-Weiss fitting to the inverse magnetic susceptibility. The temperature dependence of resistivity ρ(T ) for both compounds can be described with Mott's variable range hopping mechanism in the one-dimensional model for C r2Re O6 and the three-dimensional model for CrRe O4 , respectively. For both compounds, a weak resistivity anomaly can be discerned around TN from the temperature derivative curves, signaling the interplay of charge and spin degrees of freedom for these 3 d (Cr)-5 d (Re) coupled electron systems.
- Publication:
-
Physical Review B
- Pub Date:
- January 2018
- DOI:
- 10.1103/PhysRevB.97.014426
- Bibcode:
- 2018PhRvB..97a4426J