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Marjerrison CA, Thompson CM, Sala G, Maharaj DD, Kermarrec E, Cai Y, Hallas AM, Wilson MN, Munsie TJS, Granroth GE, Flacau R, Greedan JE, Gaulin BD, Luke GM. Cubic Re 6+ (5d 1) Double Perovskites, Ba 2MgReO 6, Ba 2ZnReO 6, and Ba 2Y 2/3ReO 6: Magnetism, Heat Capacity, μSR, and Neutron Scattering Studies and Comparison with Theory. Inorg Chem 2016; 55:10701-10713. [PMID: 27700052 DOI: 10.1021/acs.inorgchem.6b01933] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Double perovskites (DP) of the general formula Ba2MReO6, where M = Mg, Zn, and Y2/3, all based on Re6+ (5d1, t2g1), were synthesized and studied using magnetization, heat capacity, muon spin relaxation, and neutron-scattering techniques. All are cubic, Fm3̅m, at ambient temperature to within the resolution of the X-ray and neutron diffraction data, although the muon data suggest the possibility of a local distortion for M = Mg. The M = Mg DP is a ferromagnet, Tc = 18 K, with a saturation moment ∼0.3 bohr magnetons at 3 K. There are two anomalies in the heat capacity: a sharp feature at 18 K and a broad maximum centered near 33 K. The total entropy loss below 45 K is 9.68 e.u., which approaches R ln 4 (11.52 e.u.) supporting a j = 3/2 ground state. The unit cell constants of Ba2MgReO6 and the isostructural, isoelectronic analogue, Ba2LiOsO6, differ by only 0.1%, yet the latter is an anti-ferromagnet. The M = Zn DP also appears to be a ferromagnet, Tc = 11 K, μsat(Re) = 0.1 μB. In this case the heat capacity shows a somewhat broad peak near 10 K and a broader maximum at ∼33 K, behavior that can be traced to a smaller particle size, ∼30 nm, for this sample. For both M = Mg and Zn, the low-temperature magnetic heat capacity follows a T3/2 behavior, consistent with a ferromagnetic spin wave. An attempt to attribute the broad 33 K heat capacity anomalies to a splitting of the j = 3/2 state by a crystal distortion is not supported by inelastic neutron scattering, which shows no transition at the expected energy of ∼7 meV nor any transition up to 100 meV. However, the results for the two ferromagnets are compared to the theory of Chen, Pereira, and Balents, and the computed heat capacity predicts the two maxima observed experimentally. The M = Y2/3 DP, with a significantly larger cell constant (3%) than the ferromagnets, shows predominantly anti-ferromagnetic correlations, and the ground state is complex with a spin frozen component Tg = 16 K from both direct current and alternating current susceptibility and μSR data but with a persistent dynamic component. The low-temperature heat capacity shows a T1 power law. The unit cell constant of B = Y2/3 is less than 1% larger than that of the ferromagnetic Os7+ (5d1) DP, Ba2NaOsO6.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Garrett E Granroth
- Quantum Condensed Matter Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Roxana Flacau
- Canadian Neutron Beam Centre, Canadian Nuclear Laboratories , Chalk River, Ontario K0J 1J0, Canada
| | - John E Greedan
- Brockhouse Institute for Materials Research , Hamilton, Ontario L8S 4M1, Canada
| | - Bruce D Gaulin
- Brockhouse Institute for Materials Research , Hamilton, Ontario L8S 4M1, Canada.,Canadian Institute for Advanced Research , 180 Dundas Street W, Toronto, Ontario M5G 1Z8, Canada
| | - Graeme M Luke
- Brockhouse Institute for Materials Research , Hamilton, Ontario L8S 4M1, Canada.,Canadian Institute for Advanced Research , 180 Dundas Street W, Toronto, Ontario M5G 1Z8, Canada
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Wolf D, Kemmler-Sack S. The Luminescence of Nd3+ in the Polymorphic Perovskites Ba6B2W3O18 (B = Gd, Lu, Y). A Case with a Low-Lying Charge Transfer Transiton. ACTA ACUST UNITED AC 1986. [DOI: 10.1002/pssa.2210930133] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Propane Oxidation Over Mixed Metal Oxides: Perovskites, Trirutiles and Columbites. ACTA ACUST UNITED AC 1981. [DOI: 10.1016/s0167-2991(08)64727-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
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Schittenhelm HJ, Fadini A, Kemmler-Sack S. �ber hexagonale Perowskite mit Kationenfehlstellen. VIII. Schwingungsspektroskopische Untersuchungen an rhomboedrischen 18 L-Stapelvarianten vom Typ Ba6BIII2?WVI3O18. Z Anorg Allg Chem 1979. [DOI: 10.1002/zaac.19794570116] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Wischert W, Schittenhelm HJ, Kemmler-Sack S. �ber Hexagonale Perowskite mit Kationenfehlstellen. V. Strukturbestimmungen an H?Ba2Lu2/3?1/3 WO6 ? eine neue rhomboedrische Stapelvariante mit 18 Schichten. Z Anorg Allg Chem 1979. [DOI: 10.1002/zaac.19794480114] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Fadini A, Jooss I, Kemmler-Sack S, Rauser G, Rother HJ, Schillinger E, Schittenhelm HJ, Treiber U. Schwingungsspektroskopische Untersuchungen an geordneten Perowskiten A2IIBMO6. I. MO6-Oktaeder: Symmetrie, Kraftkonstanten und Abst�nde. Z Anorg Allg Chem 1978. [DOI: 10.1002/zaac.19784390104] [Citation(s) in RCA: 40] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Schittenhelm HJ, Kemmler-Sack S, Fadini A. Schwingungsspektroskopische Untersuchungen an Perowskitvarianten Ba2B0,67III?0,33MVIO6 und ihren Mischkristallen mit Ba2BIIMVIO6. Z Anorg Allg Chem 1977. [DOI: 10.1002/zaac.19774370128] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Schittenhelm HJ, Kemmler-Sack S. �ber die Polymorphie der Perowskite Ba2SE0,67WVIO6. II. Die Systeme Ba2Nd0,67(1?x) Y0,67xWO6 und Ba2Nd0,67W1?xUxO6. Z Anorg Allg Chem 1977. [DOI: 10.1002/zaac.19774310113] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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