Magnetic properties of the S = 52 anisotropic triangular chain compound Bi3FeMo2

Structure and Magnetism of an Ideal One-Dimensional Chain Antiferromagnet [C2NH8]3[Fe(SO4)3] with a Large Spin of S = 5/2

“…A more reasonable model for small η is based on the Green function method, k B T N /| J | = 4 S ( S + 1)/3 I (η), where I (η) ≈ 0.633/(η 1/2 ) (when η ≪ 1), which gives rise to a particularly small value of η < 2.5 × 10 –3 . Such a value of η is much smaller than η = 0.33 of FeSeO 3 F, η = 0.08 of Bi 2 Fe­(SeO 3 )­OCl 3 , and η = 0.01 of Bi 3 FeMo 2 O 12 As far as we are aware, no 1D chain compounds with S = 5/2 have such a small value of η, except for the recently reported FeF 3 (4,4′-bpy) with η < 3.2 × 10 –5 …”

“…Such a value of η is much smaller than η = 0.33 of FeSeO 3 F, η = 0.08 of Bi 2 Fe­(SeO 3 )­OCl 3 , and η = 0.01 of Bi 3 FeMo 2 O 12 As far as we are aware, no 1D chain compounds with S = 5/2 have such a small value of η, except for the recently reported FeF 3 (4,4′-bpy) with η < 3.2 × 10 –5 In [C 2 NH 8 ] 3 [Fe­(SO 4 ) 3 ], the interchain interaction is so small that it cannot induce long-range AFM ordering; quantum fluctuation is still operative even though the system has a classical spin S = 5/2.…”

“…20 More research studies have focused on the chains with halfinteger spins such as the S = 3/2 Heisenberg chain Na 2 Mn 3 O 7 , 21 S = 5/2 alternating chain FeSeO 3 F, 22 linear-chain SrMn(VO 4 )(OH), 23 screw chain SrMn 2 V 2 O 8 , 24 zigzag chain Ba 3 Fe 2 Ge 4 O 14 25 and Bi 2 Fe(SeO 3 )OCl 3 , 26 and triangular chain Bi 3 FeMo 2 O 12 . 27 Recently, FeF 3 (4,4′-bpy) has been reported as an ideal 1D S = 5/2 uniform chain antiferromagnet, 28 in which no long-range AFM ordering appears at T ≥ 2 K and the intrachain interaction J is fairly strong while the interchain interaction J′ is extremely small with J′/J <3.2 × 10 −5 . In these chain compounds, the emergent magnetism depends on the competition between spin, low dimensionality, intra-/interchain exchanges, and magnetic frustration.…”

Observation of anisotropic thermal expansion and Jahn-Teller effect in double perovskites Sr$_{2-x}$La$_x$CoNbO$_6$ using neutron diffraction

“…The presence of 32% disorder between the Co and Nb atoms in the present case results in the additional Co-O-Co magnetic interactions, which may be the possible reason for suppression of the long range Co-O-Nb-O-Co AFM path. This suggest that the range of the AFM ordering in the x = 0.6 sample is not long enough to produce the magetic reflection in the NPD spectra above the background level, as this sample lies at the borderline of the ordered-disordered configurations of Sr 2−x La x CoNbO 6 (x =0-1) series [18,23,40]. On the other hand, the NPD pattern reported for the x = 1 sample (with 4% B-site disorder) clearly show the additional magnetic reflections resulting from the antiferromagnetically aligned spins with the magnetic prorogation vector k= ( 1 2 0 1 2 ) [19].…”

Observation of Anisotropic Thermal Expansion and the Jahn–Teller Effect in Double Perovskites Sr2–xLaxCoNbO6 Using Neutron Diffraction

“…The presence of 32% disorder between the Co and Nb atoms in the present case results in the additional Co–O–Co magnetic interactions, which may be the possible reason for suppression of the long-range Co–O–Nb–O–Co AFM path. This suggests that the range of the AFM ordering in the x = 0.6 sample is not long enough to produce the magnetic reflection in the NPD spectra above the background level, as this sample lies at the borderline of the ordered-disordered configurations of Sr 2– x La x CoNbO 6 ( x = 0–1) series. ,, On the other hand, the NPD pattern reported for the x = 1 sample (with 4% B-site disorder) clearly shows the additional magnetic reflections resulting from the antiferromagnetically aligned spins with the magnetic prorogation vector k = ( 0 )…”