Large magnetic-field-induced strain at the magnetic order transition in triangular antiferromagnet AgCrS2

Abstract

Strain induced by a magnetic field is a common phenomenon for ferromagnets, but few antiferromagnets show large strain induced by a magnetic field. On the basis of linear strain measurements of sintered samples of triangular antiferromagnet ACrS2 (A = Cu, Ag, and Au) in magnetic fields up to 9 T, the AgCrS2 sample was found to show a large strain, yielding a large volume change over 700 ppm, which is one of the largest volume changes measured to date for an antiferromagnet. This large strain appeared only at the Néel temperature of 42 K and was not restored to its initial state when the applied magnetic field was decreased to zero; however, it was initialized by cooling the sample to far below the Néel temperature. These results suggest that the coexistence of magnetically ordered and paramagnetic phases at the first-order phase transition plays an important role. AuCrS2 showed a magnetic-field-induced strain with similar features, although it was smaller than that in AgCrS2.

Planar triangular S=3/2 magnet AgCrSe2 : Magnetic frustration, short range correlations, and field-tuned anisotropic cycloidal magnetic order

“…1), thermal expansion could so far only be measured along the crystallographic c direction, even though a comparison to the neutron data for other directions would be highly desirable. A comparison with the thermal expansion of Cr-sulphur systems (ACrS 2 , A = Cu, Ag, Au) clearly shows, as already mentioned in the discussion of the specific heat, a different behavior since in these systems the magnetic phase transition is accompanied by a structural phase transition [72]. In contrast, our results on the thermal expansion of AgCrSe 2 clearly evidence the absence of any structural phase transition across the magnetic transition.…”

“…In contrast to AgCrSe 2 , other non oxygen-based Cr triangular lattice systems within the R3m symmetry group (AgCrS 2 , CuCrS 2 ) undergo an additional structural phase transition to a lower symmetry group at low temperatures, and therefore show a pronounced anomaly associated to the simultaneous structural and magnetic order in the low temperature heat capacity [57,68,69]. Furthermore, they have negative Weiss temperatures, i.e.…”

Growth and Thermal Conductivity Study of CuCr2Se4-CuCrSe2 Hetero-Composite Crystals

“…Ternary chromium chalcogenides ACrX 2 (A = Cu, Ag; X = S, Se, Te) are attracting enormous attention in recent years because of their rich physical properties, such as ferroelectric [1,2], multiferroic [3][4][5], and large magnetic-field-induced strain [6]. For example, CuCrSe 2 has good overall thermoelectric performances of the low thermal conductivity, good electronic transport (carrier concentration can reach 1.7 × 10 20 cm −3 ), and high Seebeck coefficient (100 µV•K −1 ) at room temperature [7][8][9].…”