Helical magnetism in Sr-doped CaMn7O12 films

Noncollinear magnetism can play an important role in multiferroic materials but is relatively understudied in oxide heterostructures compared to their bulk counterparts. Using variable temperature magnetometry and neutron diffraction, we demonstrate the presence of helical magnetic ordering in CaMn 7 O 12 and Ca 1- x Sr x Mn 7 O 12 (for x up to 0.51) thin films. Consistent with bulk Ca 1- x Sr x Mn 7 O 12 , the net magnetization increases with Sr doping. Neutron diffraction confirms that the helical magnetic structure remains incommensurate at all values of x , while the fundamental magnetic wavevector increases upon Sr substitution. This result demonstrates a chemical-based approach for tuning helical magnetism in quadruple perovskite films and enables future studies of strain and interfacial effects on helimagnetism in oxide heterostructures.

[1]  J. Frederick,et al.  Deterministic and robust room-temperature exchange coupling in monodomain multiferroic BiFeO3 heterostructures , 2017, Nature Communications.

[2]  A. Herklotz,et al.  Effect of chemical pressure on the electronic phase transition in Ca 1-x Sr x Mn 7 O 12 films , 2017 .

[3]  P. Manuel,et al.  Universal magneto-orbital ordering in the divalent $A$-site quadruple perovskite manganites $A$Mn$_7$O$_{12}$ ($A$ = Ca, Sr, Cd, and Pb) , 2017, 1707.02218.

[4]  L. C. Gupta,et al.  Dramatic variation of the multiferroic properties in Sr doped Ca1-xSrxMn7O12 , 2017 .

[5]  M. L. Tacon,et al.  Soft-phonon-driven orbital order in CaMn 7 O 12 , 2016, 1610.09191.

[6]  D. Ralph,et al.  Interface-Induced Phenomena in Magnetism. , 2016, Reviews of modern physics.

[7]  C. Martin,et al.  Modulated spin helicity stabilized by incommensurate orbital density waves in a quadruple perovskite manganite , 2016, 1604.07747.

[8]  A. Belik,et al.  Differentiation between ferroelectricity and thermally stimulated current in pyrocurrent measurements of multiferroic M Mn 7 O 12 ( M = Ca , Sr, Cd, Pb) , 2016 .

[9]  A. Sobolev,et al.  Low-Temperature Structural Modulations in CdMn7O12, CaMn7O12, SrMn7O12, and PbMn7O12 Perovskites Studied by Synchrotron X-ray Powder Diffraction and Mössbauer Spectroscopy , 2016 .

[10]  Diomedes Saldana-Greco,et al.  Improper magnetic ferroelectricity of nearly pure electronic nature in helicoidal spiral CaMn 7 O 12 , 2016, 1601.03020.

[11]  Liang Xie,et al.  The structural and magnetic properties of Sr-doped multiferroic CaMn7O12 , 2015 .

[12]  A. Rappe,et al.  Electronic transition above room temperature in CaMn7O12 films , 2015 .

[13]  X. Ke,et al.  Interfacial magnetism in complex oxide heterostructures probed by neutrons and x-rays , 2015, Journal of physics. Condensed matter : an Institute of Physics journal.

[14]  A. Sobolev,et al.  High-pressure synthesis, crystal structures, and properties of CdMn7O12 and SrMn7O12 perovskites. , 2015, Inorganic chemistry.

[15]  F. Giustino,et al.  First-principles study of structurally modulated multiferroic CaMn 7 O 12 , 2015, 1502.03351.

[16]  X. Du,et al.  Identification and mechanical control of ferroelastic domain structure in rhombohedral CaMn 7 O1 2 , 2015, 1501.00667.

[17]  S. Dong,et al.  Giant electronic polarization induced by a helical spin order in SrMn7O12: First-principles calculations , 2014 .

[18]  A. Ayala,et al.  Spin-phonon and magnetostriction phenomena in CaMn7O12 helimagnet probed by Raman spectroscopy , 2014, 1410.0073.

[19]  Chong-yu Wang,et al.  Soft vibrational mode associated with incommensurate orbital order in multiferroic CaMn 7 O 12 , 2014, 1408.6957.

[20]  S. May,et al.  Magnetic Oxide Heterostructures , 2014 .

[21]  Viktor G. Hadjiev,et al.  Raman study of phonons in CaMn7O12 : effects of structural modulation and structural transition , 2014 .

[22]  H. Hwang,et al.  Multiple helimagnetic phases and topological Hall effect in epitaxial thin films of pristine and Co-doped SrFeO3 , 2013 .

[23]  Handong Sun,et al.  Magnetic properties and origins of ferroelectric polarization in multiferroic CaMn7O12 , 2013 .

[24]  X. Gong,et al.  Giant ferroelectric polarization of CaMn7O12 induced by a combined effect of Dzyaloshinskii-Moriya interaction and exchange striction. , 2012, Physical review letters.

[25]  C. Martin,et al.  Magneto-orbital helices as a route to coupling magnetism and ferroelectricity in multiferroic CaMn7O12 , 2012, Nature Communications.

[26]  C. Martin,et al.  Giant Improper Ferroelectricity in the Ferroaxial Magnet CaMn 7 O 12 , 2011, 1110.4585.

[27]  I. Takeuchi,et al.  Neutron Diffraction Investigations of Magnetism in BiFeO3 Epitaxial Films , 2011 .

[28]  E. Dagotto,et al.  Multiferroic properties of CaMn(7)O(12) , 2011, 1101.2276.

[29]  C. Eom,et al.  Magnetic structure of epitaxial multiferroic BiFe03 films with engineered ferroelectric domains , 2010 .

[30]  K. Bouzehouane,et al.  Crystallographic, magnetic, and ferroelectric structures of bulklike BiFeO3 thin films , 2008 .

[31]  E. Suard,et al.  Charge ordering in CaCuxMn7−xO12 (x = 0.0 and 0.1) compounds , 2008 .

[32]  Y. Tokura,et al.  Correlation between spin helicity and an electric polarization vector in quantum-spin chain magnet LiCu2O2. , 2008, Physical review letters.

[33]  O. Volkova,et al.  New functional materials AC3B4O12 (Review) , 2007 .

[34]  S. McKenney,et al.  3He spin filters for a thermal neutron triple axis spectrometer , 2007 .

[35]  E. Suard,et al.  Phase coexistence in the charge ordering transition in CaMn7O12 , 2002 .

[36]  B. Dabrowski,et al.  Relationship between structural parameters and the Néel temperature in Sr 1 − x Ca x MnO 3 ( 0 x 1 ) and Sr 1 − y Ba y MnO 3 ( y 0 . 2 ) , 2001 .

[37]  D. Hohlwein,et al.  Magnetic ordering in the manganese perovskite CaMn7O12 , 1999 .

[38]  M. Hervieu,et al.  MAGNETOTRANSPORT PHENOMENA IN A(MN3-XCUX)MN4O12 (A = CA, TB, TM) PEROVSKITES , 1998 .

[39]  S. Cheong,et al.  Structural effects on the magnetic and transport properties of perovskite A{sub 1{minus}x}A{sub x}{sup {prime}}MnO{sub 3} (x=0.25, 0.30) , 1997 .

[40]  L. M. Rodriguez-Martinez,et al.  Cation disorder and size effects in magnetoresistive manganese oxide perovskites. , 1996, Physical review. B, Condensed matter.

[41]  M. Marezio,et al.  High pressure synthesis and crystal structure of a new series of perovskite-like compounds CMn7O12 (C = Na, Ca, Cd, Sr, La, Nd) , 1974 .

[42]  R. M. Moon,et al.  POLARIZATION ANALYSIS OF THERMAL-NEUTRON SCATTERING. , 1969 .