Spin decoupling under a staggered field in the Gd2Ir2O7 pyrochlore

The influence of a staggered molecular field in frustrated rare-earth pyrochlores, produced via the magnetic iridium occupying the transition metal site, can generate exotic ground states, such as the fragmentation of the magnetization in the Ho compound. At variance with the Ising Ho$^{3+}$ moment, we focus on the behavior of the quasi isotropic magnetic moment of the Gd$^{3+}$ ion at the rare-earth site. By means of macroscopic measurements and neutron scattering, we find a complex situation where different components of the magnetic moment contribute to two antiferromagnetic non-collinear arrangements: a high temperature all in - all out order induced by the Ir molecular field, and Palmer and Chalker correlations that tend to order at much lower temperatures. This is enabled by the anisotropic nature of the Gd-Gd interactions and requires a weak easy-plane anisotropy of the Gd$^{3+}$ moment due to the mixing of the ground state with multiplets of higher spectral terms.

[1]  M. Vojta,et al.  Cluster-Glass Phase in Pyrochlore XY Antiferromagnets with Quenched Disorder. , 2017, Physical review letters.

[2]  C. Ritter,et al.  Magnetic structure of Tb2Ir2O7 determined by powder neutron diffraction , 2017 .

[3]  V. Simonet,et al.  Fragmentation in spin ice from magnetic charge injection , 2017, Nature Communications.

[4]  S. Petit,et al.  Long-Range Order in the Dipolar XY Antiferromagnet Er_{2}Sn_{2}O_{7}. , 2017, Physical review letters.

[5]  H. Zhou,et al.  Robust pinning of magnetic moments in pyrochlore iridates , 2017, 1705.01093.

[6]  C. Ritter,et al.  Direct determination of the spin structure of Nd2Ir2O7 by means of neutron diffraction , 2016, 1610.03968.

[7]  Han Yan,et al.  Theory of multiple-phase competition in pyrochlore magnets with anisotropic exchange with application to Yb 2 Ti 2 O 7 , Er 2 Ti 2 O 7 , and Er 2 Sn 2 O 7 , 2016, 1603.09466.

[8]  S. Petit,et al.  Spin dynamics in the presence of competing ferromagnetic and antiferromagnetic correlations inYb2Ti2O7 , 2015, 1506.01729.

[9]  J. Oitmaa,et al.  Are Multiphase Competition and Order by Disorder the Keys to Understanding Yb(2)Ti(2)O(7)? , 2015, Physical review letters.

[10]  V. Simonet,et al.  Anisotropy-Tuned Magnetic Order in Pyrochlore Iridates. , 2015, Physical review letters.

[11]  Fengyuan Yang,et al.  Enhanced weak ferromagnetism and conductivity in hole-doped pyrochlore iridateY2Ir2O7 , 2014, 1501.00615.

[12]  R. Moessner,et al.  Semi-classical spin dynamics of the antiferromagnetic Heisenberg model on the kagome lattice , 2014, 1403.7903.

[13]  M. Gingras,et al.  Fluctuation-driven selection at criticality in a frustrated magnetic system: the case of multiple-k partial order on the pyrochlore lattice. , 2013, Physical review letters.

[14]  T. Arima,et al.  Determination of long-range all-in-all-out ordering of Ir 4 + moments in a pyrochlore iridate Eu 2 Ir 2 O 7 by resonant x-ray diffraction , 2013 .

[15]  Y. Hinatsu,et al.  Metal–Insulator Transitions in Pyrochlore Oxides Ln2Ir2O7 , 2011 .

[16]  S. Petit,et al.  Spin dynamics in the ordered spin ice Tb$_2$Sn$_2$O$_7$ , 2011, 1109.1960.

[17]  M. Gingras,et al.  Rods of neutron scattering intensity in Yb2Ti2O7: compelling evidence for significant anisotropic exchange in a magnetic pyrochlore oxide. , 2010, Physical review letters.

[18]  M. Gingras,et al.  Magnetic Pyrochlore Oxides , 2009, 0906.3661.

[19]  P. Bonville,et al.  Magnetic excitations in the geometrically frustrated pyrochlore antiferromagnet Gd 2 Sn 2 O 7 studied by electron spin resonance , 2009 .

[20]  P. Cochat,et al.  Et al , 2008, Archives de pediatrie : organe officiel de la Societe francaise de pediatrie.

[21]  S. Curnoe,et al.  Structural distortion and the spin liquid state in Tb 2 Ti 2 O 7 , 2007, 0712.1703.

[22]  C. Marin,et al.  Single-ion anisotropy and transverse magnetization in the frustrated gadolinium pyrochlores , 2007 .

[23]  M. Gingras,et al.  Low-temperature specific heat and possible gap to magnetic excitations in the Heisenberg pyrochlore antiferromagnet Gd 2 Sn 2 O 7 , 2007, cond-mat/0702661.

[24]  A. Loidl,et al.  Single-ion anisotropy in the gadolinium pyrochlores studied by electron paramagnetic resonance , 2005, cond-mat/0507413.

[25]  J. R. Stewart,et al.  LETTER TO THE EDITOR: Phase transitions, partial disorder and multi-k structures in Gd2Ti2O7 , 2004 .

[26]  M. Gingras,et al.  Quantum spin fluctuations in the dipolar Heisenberg-like rare earth pyrochlores , 2004, cond-mat/0403494.

[27]  O. Cépas,et al.  Field-driven transitions in the dipolar pyrochlore antiferromagnet Gd 2 Ti 2 O 7 , 2003, cond-mat/0306638.

[28]  A. Barnes,et al.  D4c: A very high precision diffractometer for disordered materials , 2002 .

[29]  M. Green,et al.  Order in the Heisenberg pyrochlore: The magnetic structure of Gd2Ti2O7 , 2001, cond-mat/0105043.

[30]  J. Chalker,et al.  Order induced by dipolar interactions in a geometrically frustrated antiferromagnet , 1999, cond-mat/9912494.

[31]  R. Moessner,et al.  Properties of a classical spin liquid: the Heisenberg pyrochlore antiferromagnet , 1997, cond-mat/9712063.

[32]  Juan Rodríguez-Carvajal,et al.  Recent advances in magnetic structure determination by neutron powder diffraction , 1993 .

[33]  H. Capellmann,et al.  The XYZ-Difference Method with Polarized Neutrons and the Separation of Coherent, Spin Incoherent, and Magnetic Scattering Cross Sections in a Multidetector† , 1993 .

[34]  Reimers.  Absence of long-range order in a three-dimensional geometrically frustrated antiferromagnet. , 1992, Physical review. B, Condensed matter.

[35]  Xiaohao Yang,et al.  Magnetic pair distribution function analysis of local magnetic correlations. , 2014, Acta crystallographica. Section A, Foundations and advances.