We
report two novel titanium-based pnictide oxide compounds (EuF)2Ti2Pn2O (Pn = Sb, Bi), which are synthesized
by replacing Sr2+ in (SrF)2Ti2Pn2O [Structure and Physical Properties of the Layered
Pnictide-Oxides: (SrF)2Ti2
Pn
2O (Pn = As, Sb) and (SmO)2Ti2Sb2OLiuR. H.
Liu, R. H.
Chem. Mater.20102215031508] with Eu2+ using a solid-state
reaction. (EuF)2Ti2Sb2O exhibits
an obvious anomaly in resistivity and heat capacity at T ∼ 195 K, which may arise from the spin-density wave/charge-density
wave instability. Similar features are also observed in BaTi2Pn2O, (SrF)2Ti2Pn2O,
and Na2Ti2Pn2O (Pn = As and Sb) [Structure and Physical Properties of the Layered Pnictide-Oxides:
(SrF)2Ti2
Pn
2O (Pn = As, Sb) and (SmO)2Ti2Sb2OLiuR. H.
Liu, R. H.
Chem. Mater.20102215031508, Chemistry of layered d-metal pnictide
oxides and their potential as candidates for new superconductorsOzawaT. C.
Ozawa, T. C.
033003Sci. Technol. Adv. Mater.20089, Structure and physical properties for a new layered pnictide-oxide:
BaTi2As2OWangX. F.
Wang, X. F.
075702J. Phys.:
Condens. Matter.201022, and Electronic structure
of the BaTi2As2O parent compound of the titanium-based
oxypnictide superconductorXuH. C.
Xu, H. C.
155108Phys. Rev. B201489]. Magnetic susceptibility measurements indicate an antiferromagnetic
transition at T ∼ 2.5 K for (EuF)2Ti2Sb2O. In particular, the electronic specific
heat coefficients of both (EuF)2Ti2Sb2O and (EuF)2Ti2Bi2O are significantly
enhanced compared to those of (SrF)2Ti2Pn2O, Na2Ti2Pn2O, and BaTi2Pn2O,1,5,6 which may be due to a strong
electron correlation effect in this system. Thus, (EuF)2Ti2Pn2O (Pn = Sb, Bi) may provide new platforms
for studying density wave, magnetic ordering, and electron correlation
effects.
