Neutron diffraction and reflectivity studies of the Cr Néel transition in Fe/Cr (001) superlattices

Fullerton, Eric E.; Adenwalla, Shireen; Felcher, G. P.; Riggs, K. T.; Sowers, C. H.; Bader, S. D.; Robertson, J. L.

doi:10.1016/0921-4526(95)00951-5

Cited by 28 publications

(17 citation statements)

References 28 publications

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“…This differs from the experimental results of Fe/Cr(001), whose T N (D) decreases with dropping D [252,253], which could be induced by the spinfrustration effect in the vicinity of the rough Fe/Cr(001) interfaces where the interfacial exchange energy can be minimized only locally and frustration of the interfacial spins occurs since Fe and Cr have magnetical long-range order [252,253].…”

Section: Size Dependence Of the Néel Temperaturecontrasting

confidence: 54%

“…(52), (53) can also fit the experimental data of thin CoO, Cr and Ho films [128,232,252,253], it strictly hold only when D is large with the help of the adjustable parameters 0 , and C 0 , D 0 , , respectively, which are case-sensitive without clear physical meaning. Furthermore, above two relationships cannot describe the superheating T N (D) with dropping D [234,251].…”

Section: Size Dependence Of the Néel Temperaturementioning

confidence: 99%

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Size Dependence of Structures and Properties of Magnetic Materials

Jiang¹,

Lang²

2007

TONANOJ

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Due to the involvement of high portion of atomic coordination imperfection in surfaces and interfaces, the properties of magnetic nanocrystals dramatically differ from that of the corresponding bulk counterparts, which have led to a surge in both experimental and theoretical investigations in the past decades. This review summarizes the studies for these size-dependent magnetic properties, and additional thermal or phase stabilities, and mechanical properties. To interpret the above phenomena, a thermodynamic model for the size dependence and interface dependences of these properties is described, which is based on Lindemann s criterion for melting, Mott s expression for the vibrational melting entropy, and Shi s model for the size-dependent melting temperature. The model without any adjustable parameter is confirmed by a large number of experimental results, and helps us to understand the structures and properties of the magnetic nanocrystals. Moreover, other theoretical works on the above properties are also mentioned and commented.

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Section: Size Dependence Of the Néel Temperaturecontrasting

confidence: 54%

Section: Size Dependence Of the Néel Temperaturementioning

confidence: 99%

Size Dependence of Structures and Properties of Magnetic Materials

Jiang¹,

Lang²

2007

TONANOJ

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“…Assuming that each layer in the MML can be described by the bulk values of Fe and magnetic Cr and assuming perfect interfaces leads to γ M L = 3.6 mJ/K 2 mol. Using the more realistic non-magnetic value for Cr [8] increases γ M L only slightly to 4.3 mJ/K 2 mol, half of the measured value. The absence of electronic band structure calculation complicates the interpretation of this result: purely electronic effects, effective mass enhancement, presence of other phases with high electronic γ and other type of excitations are hard to separate.…”

Section: Resultsmentioning

confidence: 98%

“…In thin films, the magnetic properties of Cr are strongly modified by the stress and the presence of ferromagnetic capping layers as observed by neutron diffraction [4]. In Fe/Cr (001) epitaxial MML, Fullerton et al [8] showed the loss of magnetic long range order in Cr layers for thicknesses t Cr < 42Å. The electronic structure of these thin non-magnetic Cr layers is not well documented in spite of its importance for the calculations of the GMR.…”

Section: Introductionmentioning

confidence: 99%

Enhancement of the electronic contribution to the low-temperature specific heat of an Fe/Cr magnetic multilayer

et al. 2002

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We measured the low temperature specific heat of a sputtered (F e 23Å /Cr 12Å ) 33 magnetic multilayer, as well as separate 1000Å thick Fe and Cr films. Magnetoresistance and magnetization measurements on the multilayer demonstrated antiparallel coupling between the Fe layers. Using microcalorimeters made in our group, we measured the specific heat for 4 < T < 30 K and in magnetic fields up to 8 T for the multilayer. The low temperature electronic specific heat coefficient of the multilayer in the temperature range 4 < T < 14 K is γ M L = 8.4 mJ/K 2 g − at. This is significantly larger than that measured for the Fe or Cr films (5.4 and. 3.5 mJ/K 2 mol respectively). No magnetic field dependence of γ M L was observed up to 8 T .These results can be explained by a softening of the phonon modes observed in the same data and the presence of an Fe-Cr alloy phase at the interfaces.75.70 (magnetic multilayer), 75.40 (specific heat of magnetic materials) Typeset using REVT E X 1

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“…[11][12][13][14][15][16][17] Fullerton et al used an empirical formula to describe T N (K) function of Ho 18 and Cr thin films. 19,20 More recently, Jiang et al adapted their model of melting point suppression to the T C (or T N ) of the nanomaterials. 21,22 They also consider that the value of ∆T N (K)/T N (∞) is equal to ∆T C (K)/T C (∞).…”

Section: Introductionmentioning

confidence: 99%

The effect of surface and interface on Neel transition temperature of low-dimensional antiferromagnetic materials

et al. 2015

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Incorporating the bond order-length-strength (BOLS) notion with the Ising premise, we have modeled the size dependence of the Neel transition temperature (TN) of antiferromagnetic nanomaterials. Reproduction of the size trends reveals that surface atomic undercoordination induces bond contraction, and interfacial hetero-coordination induces bond nature alteration. Both surface and interface of nanomaterials modulate the TN by adjusting the atomic cohesive energy. The TN is related to the atomic cohesive/exchange energy that is lowered by the coordination number (CN) imperfection of the undercoordinated atoms near the surface and altered by the changed bond nature of epitaxial interface. A numerical match between predictions and measurements reveals that the TN of antiferromagnetic nanomaterials declines with reduced size and increases with both the strengthening of heterogeneous bond and the increase of the bond number.

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Neutron diffraction and reflectivity studies of the Cr Néel transition in Fe/Cr (001) superlattices

Cited by 28 publications

References 28 publications

Size Dependence of Structures and Properties of Magnetic Materials

Size Dependence of Structures and Properties of Magnetic Materials

Enhancement of the electronic contribution to the low-temperature specific heat of an Fe/Cr magnetic multilayer

The effect of surface and interface on Neel transition temperature of low-dimensional antiferromagnetic materials

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