Antiferromagnetic-to-ferromagnetic transition in metallic Tl1−xKxCo2Se2 (0 ⩽ x ⩽ 1.0) with ThCr2Si2-type structure

Lattice collapse and the magnetic phase diagram ofSr1−xCaxCo2P2Jia1, Williams2, Stephens3 et al. 2009Phys. Rev. B644420View full textAdd to dashboardCite

“…The correlation between the magnetic ordering temperature and the Co-P-Co angle and Co-Co distance indicates that both superexchange and direct exchange are important; when the Co-P-Co angle and Co-Co separation reach a maximum, a FM-like ground state appears and the ordering temperature reaches its maximum value. Although details of the magnetic structure of this FM-like ground state are unknown, AFM to FM transitions strongly correlated to the shape of CoX 4 tetrahedra have been seen in other Co compounds in this structure type 21 . For x > 0.9, the P-P bond is fully formed and the Co-P-Co angle decreases with x, leading to an AFM ground state with slightly lower T N .…”

Longitudinal spin fluctuations in thermal and magnetic properties of TlCo2Se2−xSx

“…Thus, solid solutions Tl 1Àx K x Co 2 Se 2 are antiferromagnets for xo0:5 at low temperatures while they are ferromagnets for x > 0:5 [7]. In this latter case, the population of d-electrons remains unchanged at chemical substitution, but the difference in ionic radii of interchanging elements comes into play, affecting mainly the distance between the metal sheets.…”

Incommensurate Cu/Co Ordering in the TlCo2−xCuxSe2 (x∼1) System

“…The analogous expressions to Eq. [3] above are [5] for M1 to M4 and [6] for M5 to M8. Because (r + !r + ), (r + !r + ), etc.…”

“…Keep in mind that the perpendicular space average fractional co-ordinate xN I ,q ) (r I #T)# " a* ) (r I #T)# in Eqs. [3] and [4] below is really simply a label specifying which particular average structure unit cell is being referred to (9}12).…”

“…Systematic application of the superspace-generating operations gives the symmetry-compatible compositional and displacive AMFs (9) as follows, [3] for the compositional AMF describing the Co/Cu ion ordering and…”