Highly frustrated magnetism in SrHo2O4: Coexistence of two types of short-range order

Abstract

SrHo 2 O 4 is a geometrically frustrated magnet in which the magnetic Ho 3+ ions form honeycomb layers connected through a network of zigzag chains. At low-temperature two distinct types of short-range magnetic order can be inferred from single-crystal diffraction data, collected using both polarized and unpolarized neutrons. In the (hk0) plane the diffuse scattering is most noticeable around the k = 0 positions and its intensity rapidly increases at temperatures below 0.7 K. In addition, planes of diffuse scattering at Q = (hk ± l 2 ) are visible at temperatures as high as 4.5 K. These planes coexist with the broad peaks of diffuse scattering in the (hk0) plane at low temperatures. Correlation lengths associated with the broad peaks are L ≈ 150Å in the a-b plane and L ≈ 190Å along the c axis, while the correlation length associated with the diffuse scattering planes is L ≈ 230Å along the c axis at the lowest temperature. Both types of diffuse scattering are elastic in nature. The highly unusual coexistence of the two types of diffuse scattering in SrHo 2 O 4 is likely to be the result of the presence of two crystallographically inequivalent sites for Ho 3+ in the unit cell.

Magnetic ordering in the frustratedJ1−J2Ising chain candidateBaNd2O4

“…SrHo 2 O 4 shows very similar magnetism to the Er analogue with coexisting Néel and UUDD ordered states, although the correlation length of both states is finite [19][20][21]. As in the Er case, the two different structures can likely be associated with the two types of Ho zigzag chains.…”

Evolution of spin correlations in SrDy2O4 in an applied magnetic field

“…In SrEr 2 O 4 , a k = 0 long-range antiferromagnetic order with magnetic moments parallel to the c axis on one Er site and a quasi-one-dimensional (1D) short-range antiferromagnetic order with the moments along the a axis on another Er site are found to coexist down to the lowest temperatures [8,9]. In SrHo 2 O 4 , the magnetic structure is similar to that of SrEr 2 O 4 , but the k = 0 component has only a limited correlation range and the magnetic moments in the quasi-1D structure point along the b axis [10,11]. In SrYb 2 O 4 , the structure is reported to be a noncollinear k = 0 antiferromagnet in which the magnetic moments of two inequivalent Yb ions lie in the ab plane, but have different moment sizes and directions [12].…”

Spin-liquid ground state in the frustratedJ1−J2zigzag chain systemBaTb2O4Aczel1, Li2, Garlea3 et al. 2015Phys. Rev. B141110View full textAdd to dashboardCite

“…However, a variety of magnetic phases have been discovered in the intermediate regime for the R ionic radii that are not easily explained by previous theoretical work. These phases include coexisting long-range Néel and short-range double Néel order in SrEr 2 O 4 (r = 0.94Å) 17,25 , coexisting short-range Néel and short-range double Néel order in SrHo 2 O 4 (r = 0.90Å) 19,26,27 , incommensurate magnetic order in SrTb 2 O 4 (r = 0.92Å) 28 , short-range magnetic order in SrDy 2 O 4 (r = 0.91Å) 18,29 , and no magnetic ordering of any kind in SrTm 2 O 4 (r = 0.88Å) 30 . It is also interesting to note that long-range order observed in this family has often been found to arise from only one rare earth site.…”