Dominant ferromagnetism in the spin-1/2 half-twist ladder 334 compounds, Ba₃Cu₃In₄O₁₂and Ba₃Cu₃Sc₄O₁₂

Kagome-like chains with anisotropic ferromagnetic and antiferromagnetic interactions

“…Such ferromagnetic model has been studied in Refs. [17,18] and it gives rather adequate description of the paramagnetic phase of real compounds. Though in the kagome chain considered by us the AF interaction J b is not small and corresponds to special model parameter we believe that this model as well as the model (a) show rather unusual properties which can be observed in compounds of similar geometrical structure.…”

“…The isotropic kagome-chain (b) with ∆ 1 = ∆ 2 = 1 is especially interesting because it is a minimal model for a description of an interesting class of quasi- [16][17][18][19][20] and the form of the HamiltonianĤ b reflects an unusual topology of these copper oxides. These oxides represent half-twist ladders in which successive CuO 4 plaquettes are corner shared with their planes perpendicular to each other.…”

Spin-flop and antiferromagnetic phases of the ferromagnetic half-twist ladder compounds Ba3Cu3In4O12and Ba3Cu3Sc4O12

“…Theory indicates the possibility of exotic ground states (GS) in FM/AFM chains with isotropic or anisotropic exchange [15][16][17][18][19][20]. Such chains include [21].…”

“…Both compounds have FM exchange J 1 < 0 within the ladders and both undergo phase transitions [21,23,24] on cooling that clearly imply 3D…”

“…The crystals are tetragonal with half-twist ladders running along the c-axis [21][22][23][24]. There are two distinct Cu …”