title: Pb2MnTeO6 Double Perovskite: An Antipolar Anti-ferromagnet.
abstract: Pb2MnTeO6, a new double perovskite, was synthesized. Its crystal structure was determined by synchrotron X-ray and powder neutron diffraction. Pb2MnTeO6 is monoclinic (I2/m) at room temperature with a regular arrangement of all the cations in their polyhedra. However, when the temperature is lowered to ∼120 K it undergoes a phase transition from I2/m to C2/c structure. This transition is accompanied by a displacement of the Pb atoms from the center of their polyhedra due to the 6s(2) lone-pair electrons, together with a surprising off-centering of Mn(2+) (d(5)) magnetic cations. This strong first-order phase transition is also evidenced by specific heat, dielectric, Raman, and infrared spectroscopy measurements. The magnetic characterizations indicate an anti-ferromagnetic (AFM) order below TN ≈ 20 K; analysis of powder neutron diffraction data confirms the magnetic structure with propagation vector k = (0 1 0) and collinear AFM spins. The observed jump in dielectric permittivity near ∼150 K implies possible anti-ferroelectric behavior; however, the absence of switching suggests that Pb2MnTeO6 can only be antipolar. First-principle calculations confirmed that the crystal and magnetic structures determined are locally stable and that anti-ferroelectric switching is unlikely to be observed in Pb2MnTeO6.
authors.affiliation: Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey , 610 Taylor Road, Piscataway, New Jersey 08854, United States.
authors.forename: Maria
authors.initials: M
authors.lastname: Retuerto
authors.affiliation: Institute of Physics, The Czech Academy of Sciences , Na Slovance 2, 18221 Prague 8, Czech Republic.
authors.forename: Stella
authors.initials: S
authors.lastname: Skiadopoulou
authors.affiliation: Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey , 610 Taylor Road, Piscataway, New Jersey 08854, United States.
authors.forename: Man-Rong
authors.initials: MR
authors.lastname: Li
authors.affiliation: EMAT, University of Antwerp , Groenenborgerlaan 171, Antwerp B-2020, Belgium.|Chemistry Department, Moscow State University , 119991 Moscow, Russia.
authors.forename: Artem M
authors.initials: AM
authors.lastname: Abakumov
authors.affiliation: Department of Physics and Astronomy, Rutgers, The State University of New Jersey , 136 Frelinghuysen Road, Piscataway, New Jersey 08854, United States.
authors.forename: Mark
authors.initials: M
authors.lastname: Croft
authors.affiliation: Department of Physics and Astronomy, Rutgers, The State University of New Jersey , 136 Frelinghuysen Road, Piscataway, New Jersey 08854, United States.
authors.forename: Alexander
authors.initials: A
authors.lastname: Ignatov
authors.affiliation: Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey , 610 Taylor Road, Piscataway, New Jersey 08854, United States.
authors.forename: Tapati
authors.initials: T
authors.lastname: Sarkar
authors.affiliation: Department of Applied and Engineering Physics, Cornell University , Ithaca, New York 14853, United States.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Abbett
authors.affiliation: Institute of Physics, The Czech Academy of Sciences , Na Slovance 2, 18221 Prague 8, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Pokorný
authors.affiliation: Institute of Physics, The Czech Academy of Sciences , Na Slovance 2, 18221 Prague 8, Czech Republic.
authors.forename: Maxim
authors.initials: M
authors.lastname: Savinov
authors.affiliation: Institute of Physics, The Czech Academy of Sciences , Na Slovance 2, 18221 Prague 8, Czech Republic.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Nuzhnyy
authors.affiliation: Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University , Ke Karlovu 5, 12116 Prague 2, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Prokleška
authors.affiliation: Photon Sciences Directorate, Brookhaven National Laboratory , Upton, New York, United States.
authors.forename: Milinda
authors.initials: M
authors.lastname: Abeykoon
authors.affiliation: Department of Physics and Astronomy, State University of New York , Stony Brook, New York 11794 United States.
authors.forename: Peter W
authors.initials: PW
authors.lastname: Stephens
authors.affiliation: Spallation Neutron Source, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
authors.forename: Jason P
authors.initials: JP
authors.lastname: Hodges
authors.affiliation: Institute of Physics, The Czech Academy of Sciences , Na Slovance 2, 18221 Prague 8, Czech Republic.
authors.forename: Přemysl
authors.initials: P
authors.lastname: Vaněk
authors.affiliation: Department of Applied and Engineering Physics, Cornell University , Ithaca, New York 14853, United States.
authors.forename: Craig J
authors.initials: CJ
authors.lastname: Fennie
authors.affiliation: Department of Physics and Astronomy, Rutgers, The State University of New Jersey , 136 Frelinghuysen Road, Piscataway, New Jersey 08854, United States.
authors.forename: Karin M
authors.initials: KM
authors.lastname: Rabe
authors.affiliation: Institute of Physics, The Czech Academy of Sciences , Na Slovance 2, 18221 Prague 8, Czech Republic.
authors.forename: Stanislav
authors.initials: S
authors.lastname: Kamba
authors.affiliation: Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey , 610 Taylor Road, Piscataway, New Jersey 08854, United States.
authors.forename: Martha
authors.initials: M
authors.lastname: Greenblatt