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PrMn 7 O 12 Rhombo : magnetic peaks unindexed. Bank 2. Bank 1. k=?. Bank 4. 2K. 140K. Bank 3. Bank 5. Bank 6. PrMn 7 O 12 Rhombo at 140K showing quite a few impurity peaks. PrMn 7 O 12 Monoclinic : obviously, a k=(0 0 0) structure (magnetic on top of nuclear). 150K. 2K. Bank 2.
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PrMn7O12 Rhombo : magnetic peaks unindexed Bank 2 Bank 1 k=? Bank 4 2K 140K Bank 3 Bank 5 Bank 6
PrMn7O12 Monoclinic : obviously, a k=(0 0 0) structure (magnetic on top of nuclear) 150K 2K Bank 2 Bank 1 Bank 4 Bank 3 k=(000) Bank 5 Bank 6
PrMn7O12 Monoclinic at 2K indexed with k=(0 0 0) propagation vector But A-type structure must have k=(0 1 0): structure cannot be A-type S’=S.exp(2ip.k.t) S’=-S (S’=S for k=(0 0 0)) S’ t=(½ ½ ½) S S A-type Nuc Mag: H+k k=(0 1 0)
PrMn7O12 Monoclinic at 2K indexed with k=(0 0 0) propagation vector Prelim solution involving only Mn B-site C-type
Conclusions Monoc phase : • On dataset at RT, and 150K and 2K in cryo (10 times worse statistics because of cryo bckgd) • No visible structural transition down to 2K and fit not “exceptional” (R_B>10%) • mag structure k=(000) but no final model (check for A-site cation contrib/other models.…) Rhombo phase: • only 2K and 140K collected in cryo • as for the monoc sample, no visible structural transition down to 2K and relatively bad fits (R_B>10%) • more visibly impure, propagation vector(s) indexing magnetic reflections yet unknown