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  Willenberg, B.; Schaepers, M.; Wolter, A.U.B.; Drechsler, S.-L.; Reehuis, M.; Hoffmann, J.-U.; Buechner, B.; Studer, A.J.; Rule, K.C.; Ouladdiaf, B.; Suellow, S.; Nishimoto, S.: Complex Field-Induced States in Linarite PbCuSO₄(OH)₂ with a Variety of High-Order Exotic Spin-Density Wave States. Physical Review Letters 116 (2016), p. 047202/1-5

10.1103/PhysRevLett.116.047202
Open Accesn Version

Abstract:
Low-temperature neutron diffraction and NMR studies of field-induced phases in linarite are presented for magnetic fields H∥b axis. A two-step spin-flop transition is observed, as well as a transition transforming a helical magnetic ground state into an unusual magnetic phase with sine-wave-modulated moments ∥ H. An effective J˜1−J˜2 single-chain model with a magnetization-dependent frustration ratio αef f = −J˜2/J˜1 is proposed. The latter is governed by skew interchain couplings and shifted to the vicinity of the ferromagnetic critical point. It explains qualitatively the observation of a rich variety of exotic longitudinal collinear spin-density wave, SDWp, states (9 ≥ p ≥ 2).