Neutron diffraction evidence for magnetic phase transition in Europium selenide

Fischer, Peter; Hälg, W.; Wartburg, W. von; Schwob, P.; Vogt, O.

doi:10.1007/bf02422568

Cited by 17 publications

(3 citation statements)

References 19 publications

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“…As the lattice parameter increases from EuO to EuTe, a ferromagnetic ordered state of moments localized on Eu ions appear in EuO (T C ≈ 69 K) and in EuS (T C ≈ 16.7 K), 1,2 while EuSe and EuTe show collinear antiferromagnetic ordering with T N ≈ 4.2 K, T N ≈ 9.8 K respectively. 3,4 In these chalcogenide compounds, the S ground state of Eu 2+ ions and their simple face centered cubic (FCC) magnetic lattice facilitate testings of the Heisenberg model of ferromagnetism and theories of critical phenomena. [5][6][7][8][9] A variety of applications were proposed or implemented utilizing these magnetic semiconductors.…”

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confidence: 99%

Pulsed laser deposition of high-quality thin films of the insulating ferromagnet EuS

Yang¹,

Zhao²,

Zhang³

et al. 2014

Appl. Phys. Lett.

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High-quality thin films of the ferromagnetic insulator europium(II) sulfide (EuS) were fabricated by pulsed laser deposition on Al 2 O 3 (0001) and Si (100) substrates. A single orientation was obtained with the [100] planes parallel to the substrates, with atomic-scale smoothness indicates a near-ideal surface topography. The films exhibit uniform ferromagnetism below 15.9 K, with a substantial component of the magnetization perpendicular to the plane of the films. Optimization of the growth condition also yielded truly insulating films with immeasurably large resistance. This combination of magnetic and electric properties open the gate for novel devices that require a true ferromagnetic insulator.Over more than 50 years a wealth of new effects and properties have been discovered in binary lanthanide compounds. In particular, compounds of europium with elements of the sixth group (O,S,Se,Te) exhibit a rocksalt (NaCl)-type crystal structure with ordered magnetic states at low temperatures. As the lattice parameter increases from EuO to EuTe, a ferromagnetic ordered state of moments localized on Eu ions appear in EuO (T C ≈ 69 K) and in EuS (T C ≈ 16.7 K), 1,2 while EuSe and EuTe show collinear antiferromagnetic ordering with T N ≈ 4.2 K, T N ≈ 9.8 K respectively. 3,4 In these chalcogenide compounds, the S ground state of Eu 2+ ions and their simple face centered cubic (FCC) magnetic lattice facilitate testings of the Heisenberg model of ferromagnetism and theories of critical phenomena. 5-9 A variety of applications were proposed or implemented utilizing these magnetic semiconductors. 10-12 A class of magnetoelectric applications, such as π-Josephson junctions for quantum qubits 13-15 and recently proposed topological magnetoelectric effect associated with the surface state of topological insulators, 16-20 require fabrication of highquality insulating ferromagnet thin films with robust magnetic properties.Here we focus on EuS, which is a semiconductor with an indirect energy gap between the 4f 7 Eu states and the conduction band minimum at 300 K is 1.65 eV. [21][22][23] The lattice parameter of bulk crystals of EuS is a 0 = 5.967Å, with a ferromagnetic Curie temperature T C ≈ 16.7 K. When strained, the lattice constant change is accompanied by a change in Curie temperature, e.g. thin films of EuS grown on KCl show an increase in T C by as much as 2 K, due to compression induced by differential expana) Electronic mail: qiyang@stanford.edu sions of the film and substrate. 24 At the same time, very thin films will exhibit slightly lower T C due to dimensionality reduction. 25 However, although good electric insulation (ρ ∼ 10 4 Ω·cm) was obtained in high-quality single crystals, difficulties in material fabrication lead to disorder and unintentional doping, which may drastically reduce the resistivity to as low as ρ ∼ 10 −2 Ω·cm. 2,26 Such reduction in resistivity was found to be accompanied by increased Curie temperatures due to interactions between charge carriers and the Eu 2+ ions. 1,26-28 Particularly for t...

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confidence: 99%

Pulsed laser deposition of high-quality thin films of the insulating ferromagnet EuS

Yang¹,

Zhao²,

Zhang³

et al. 2014

Appl. Phys. Lett.

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“…17 At high temperatures above ∼ 100 K the magnetic susceptibility follows for both field with the literature for EuSe. 17,21,22 In Fig. 5 the field dependences of the magnetization for the external field applied perpendicular and parallel to the surface are shown, respectively, documenting that the easy magnetization direction lies within the plane.…”

Section: A Bulk Magnetometrymentioning

confidence: 88%

Search for enhanced magnetism at the interface between Bi2Se3 and EuSe

et al. 2021

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Enhanced magnetism has recently been reported for the topological-insulator/ferromagnet interface Bi 2 Se 3 /EuS with Curie temperatures claimed to be raised above room temperature from the bulk EuS value of 16 K. Here we investigate the analogous interface Bi 2 Se 3 /EuSe. EuSe is a low-temperature layered ferrimagnet that is particularly sensitive to external perturbations. We find that superconducting quantum interference device (SQUID) magnetometry of Bi 2 Se 3 /EuSe heterostructures reveals precisely the magnetic phase diagram known from EuSe, including the ferrimagnetic phase below 5 K, without any apparent changes from the bulk behavior. Choosing a temperature of 10 K to search for magnetic enhancement, we determine an upper limit for a possible magnetic coercive field of 3 mT. Using interface sensitive x-ray absorption spectroscopy we verify the magnetic divalent configuration of the Eu at the interface without contamination by Eu 3+ , and by x-ray magnetic circular dichroism (XMCD) we confirm at the interface the magnetic hysteresis obtained by SQUID. XMCD data obtained at 10 K in a magnetic field of 6 T indicate a magnetic spin moment of m z,spin = 7 µ B /Eu 2+ , in good agreement with the SQUID data and the expected theoretical moment of Eu 2+ . Subsequent XMCD measurements in zero field show, however, that sizable remanent magnetization is absent at the interface for temperatures down to about 10 K.

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“…Particularly for EuSe, several descriptions of its phase diagram can be found. In 1969, a neutron-diffraction study of EuSe by Fischer et al 9 identified a ↑↑ ↓↓ ͑type-I͒ AFM state at 4.2 K. At 1.9 K they observed coexistence of the ↑↓ ↑↓ AFM and the ↑↑↓ ferrimagnetic phases. The three observed magnetic orderings, in which successive ͑111͒ planes order ↑↑ ↓↓, ↑↓ ↑↓, and ↑↑↓, are schematically represented in Fig.…”

Section: +mentioning

confidence: 99%