| Abstract
| - Na2Ln2Ti3-xMnxO10 (Ln = Sm, Eu, Gd, and Dy; 0 ≤ x ≤ 1), a new series of triple-layerRuddlesden−Popper phases, were synthesized by direct solid-state reaction. The smallerlanthanides enhance manganese solubility in the parent titanate, and an optimized syntheticapproach allows Na2Ln2Ti3-xMnxO10 to be stabilized relative to competing single-layer andcubic phases. The X-ray diffraction patterns of Na2Ln2Ti3-xMnxO10 can be indexed on atetragonal unit cell with a doubled a axis. The Na2Ln2Ti3-xMnxO10 phases undergo ionexchange, forming A2Ln2Ti3-xMnxO10 (A = Li, NH4) by exchange in the molten nitrates.Na2Ln2Ti3-xMnxO10 is also amenable to divalent ion exchange, evidenced by the formationof AIIGd2Ti2MnO10 (AII = Mg, Ca) by ion exchange in aqueous MgCl2 and Ca(NO3)2,respectively. Temperature-dependent magnetic susceptibility measurements indicate thatthe Na2Ln2Ti3-xMnxO10 phases are paramagnetic and suggest the onset of weak magneticordering at low temperatures (<10 K).
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