Short-range magnetic ordering in the highly frustrated pyrochlore systemsFeF3andMn2

Abstract

FeF, and Mn2Sb207 elhi it 7 ex ibit long-range magnetic order at 1 5.5 netic susceptibility data fo th or ese compounds show a stron de r er at .5 and 13 K, respectively. B lk u magations from a Curie-Wei -1 b h ssaw e avior far above the orderin tern a s rong ependence on sample histor d d y an evlbuted to short-range order e or ering temperatures. These effects a tt ' d b h }1' hl fr tdl tti g a e attlce of corner-sharin tetr above T eu ronl raction data given clear evidence T, . Fo ' 1 i ofth d t ' ld F in erms o spin-spin corr 1 t' e a ions out to the f u ion unction g o oo to s e serve strong antiferromagnetic first-nei hbor n ir -neighbor, spin-spin correlations.ig or, and ferromagnetic second-

Relief and generation of frustration in pyrochlore magnets by single-ion anisotropy

“…Such a state has been known for a long time to occur in the pyrochlore antiferromagnet FeF 3 , which is one of the few antiferromagnets on this lattice which exhibit long-range order. 10,11 However, the anisotropy in this magnet, estimated at E anis Ͻ0.1 K, 12 is too weak to account for an ordering temperature around 15 K. In fact, in Monte Carlo simulations, we have verified that ordering for ͉D/J͉Ӷ1 occurs at an ordering temperature T c , proportional to D, around ͉T c /D͉Ӎ0.5. Reimers and co-workers 4,11 have proposed that four-sublattice long-range order arises from ferromagnetic third-nearest-neighbor interactions.…”

Low-temperature properties of classical geometrically frustrated antiferromagnets

“…This description neglects various additional featuressuch as anisotropy, [35][36][37][38][39] -which can play an important role in real materials, particularly near and below T F . However, it may provide a good treatment for the temperature window T < T F ≪ |Θ CW |, and its simplicity should make it well-suited for capturing the generic features of these systems, as well as providing a basis for future investigations incorporating additional interactions or quantum fluctuations.…”

NaCaNi2F7: A frustrated high-temperature pyrochlore antiferromagnet withS=1NKrizan1, Cava2 2015Phys. Rev. B484550View full textAdd to dashboardCite

“…11,12 While single crystals are available of Y 2 Mo 2 O 7 , other transition-metal-based traditional oxide pyrochlores, many of which show antiferromagnetic interactions and exhibit glassy behavior, are not available as large single crystals and do not show the same level of frustration as the fluorides. [13][14][15][16] There is theoretical interest in the FeF 3 pyrochlore, but unfortunately, the methods employed for its synthesis likely preclude the growth of this material as large single crystals. 15,17,18 In contrast, the S = 1 NaCaNi 2 F 7 and S = 3/2 NaCaCo 2 F 7 and NaSrCo 2 F 7 fluoride pyrochlores have now been grown as cm-scale single crystals, suggesting that transition metal fluorides have the potential to develop into a significant and readily accessible new family of geometrically frustrated magnets.…”

“…[13][14][15][16] There is theoretical interest in the FeF 3 pyrochlore, but unfortunately, the methods employed for its synthesis likely preclude the growth of this material as large single crystals. 15,17,18 In contrast, the S = 1 NaCaNi 2 F 7 and S = 3/2 NaCaCo 2 F 7 and NaSrCo 2 F 7 fluoride pyrochlores have now been grown as cm-scale single crystals, suggesting that transition metal fluorides have the potential to develop into a significant and readily accessible new family of geometrically frustrated magnets. 4,5 …”