Metamagnetism, giant magnetoresistance and magnetocaloric effects in RCo2-based compounds in the vicinity of the Curie temperature

Duc, Nguyen Huu; Anh, Do Thi Kim; Brommer, P.E.

doi:10.1016/s0921-4526(02)01099-2

Cited by 186 publications

(136 citation statements)

References 9 publications

Supporting

Mentioning

104

Contrasting

Unclassified

Order By: Relevance

“…Therefore, there is a strong correlation between the lattice parameter and Co magnetism in RCo 2 -based compounds. Recent results on MCE and MR seem to favor 7.22 Å as the critical lattice parameter to observe IEM and FOT in RCo 2 compounds [3]. As mentioned above, there are several experimental results in the literature that are in agreement with the predictions of Khmelevskyi and Mohn model.…”

Section: Resultssupporting

confidence: 69%

“…1 that the magnetization changes abruptly at T C in DyCo 2 and the transition smears gradually with Si concentration. It has already been reported that DyCo 2 shows FOT and this is attributed to the IEM [3,5]. According to the model by Khmelevskyi and Mohn, the lattice parameter, 'a' of DyCo 2 is well within the range 7:05 , a , 7:22 A; thereby satisfying the condition for IEM.…”

Section: Resultsmentioning

confidence: 68%

“…It is of interest to note that DS max M for TbCo 2 , which exhibits SOT is 6.5 J Kg 21 K 21 ðDH ¼ 5 TÞ: The fact that this value is not negligible compared to that of DyCo 2 , suggests that the transition in TbCo 2 is predominantly SOT, but has some signature of FOT. MR studies have also shown that maximum MR in TbCo 2 is about 17% whereas it is about 30% in DyCo 2 and 60% for HoCo 2 [3]. In this context, it is of importance to note that Khmelevskyi and Mohn model predicts conditions favoring IEM in TbCo 2 [5].…”

Section: Resultsmentioning

confidence: 95%

“…4(a) and (b [3]. The reason for such large entropy change in these compounds is mainly the FOT at T C : In addition, the structural transitions associated with the magnetic ordering may also contribute to the MCE.…”

Section: Resultsmentioning

confidence: 99%

“…Compounds exhibiting first order transitions (FOT) are potential candidates for applications based on magnetocaloric effect (MCE) and magnetoresistance (MR) [2]. Among the various R -TM intermetallics, RCo 2 (R ¼ Dy, Ho and Er) compounds have received considerable attention owing to the presence of FOT at their ordering temperatures ðT C Þ [3]. It has been found that the FOT in these compounds is due to the onset of itinerant electron metamagnetism (IEM), caused by the exchange field of the rare earth [4].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Itinerant electron metamagnetism and magnetocaloric effect in Dy(Co,Si)2

Singh

Суреш

Nigam

2003

Solid State Communications

View full text Add to dashboard Cite

Itinerant electron metamagnetism in DyðCo 1-x Si x Þ 2 compounds was studied in the light of a recent theoretical model based on magnetovolume effect and spin fluctuations. The nature of the magnetic transition in these compounds was analyzed within the framework of this model. The magnetocaloric effect in these compounds has been calculated and correlated with the strength of itinerant electron metamagnetism. The domain wall pinning effect was found to be dominant at low temperatures.

show abstract

Section: Resultssupporting

confidence: 69%

Section: Resultsmentioning

confidence: 68%

Section: Resultsmentioning

confidence: 95%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Itinerant electron metamagnetism and magnetocaloric effect in Dy(Co,Si)2

Singh

Суреш

Nigam

2003

Solid State Communications

View full text Add to dashboard Cite

show abstract

CMA's as Magnetocaloric Materials

Kobe

Podmiljsak

McGuiness

et al. 2010

Complex Metallic Alloys

View full text Add to dashboard Cite

Magnetic‐Instability‐Induced Giant Magnetoelectric Coupling

et al. 2008

View full text Add to dashboard Cite

Understanding the coupling between magnetism and ferroelectricity is of high fundamental and technological importance. [1][2][3][4][5] For example, a sufficiently strong coupling between magnetic and dielectric properties may enable switching of the magnetization by means of an electric field, thereby drastically reducing the thermal power needed for a magnetic memory. If electric writing and magnetic reading were to be used, one of the layers in spin valves composed of ferromagnetic and magnetoelectric layers would no longer have to be pinned. [6] Giant magnetoelectric materials facilitate highly efficient elastic interactions and a strong magnetic response to an electric field (or vice versa) via magnetostriction and piezoelectric effects. [7,8] Several materials possess both ferroelectricity and a co-operative magnetism; however, the coupling between these properties is not necessarily large. The structural and electronic circumstances that would favor a large coupling remain unexplored, partly due to the lack of materials with a large coupling. Here we report that such a large coupling occurs in BiCoO 3 , for which an external electric field can induce a strong magnetic response by changing the spin-state of cobalt from a magnetic high spin (HS) state to a nonmagnetic low spin (LS) state. The simultaneous presence of strong electron-electron interaction within the transition metal d manifold and a sizable hopping interaction strength between the transition metal d and oxygen p states are primarily responsible for a wide range of properties exhibited by perovskite-like oxides. Several ferroelectric perovskites undergo a phase transition from a high-temperature, high-symmetry phase that behaves as an ordinary dielectric to a spontaneously polarized phase at low temperature. Considerable research activities are focused on understanding the nature of and the driving force for such ferroelectric transitions. The electric and magnetic properties of cobaltites depend on the spin state of the Co ions, that is, whether they are in LS, intermediate spin (IS), or HS states (simplified pure ionic limit). For example, LaCoO 3 is a diamagnetic insulator at low temperature and transforms to the paramagnetic state at 90 K due to an LS-IS transition. [9,10] Metamagnetism from spin-state transitions may give rise to exciting phenomena such as giant magnetoresistance, [11] giant magnetocaloric effect, [12] shape memory effect, [13] etc. We show presently that metamagnetism can also lead to giant magnetoelectric coupling. Generally, spin-state transitions are induced by hole/electron doping, temperature, magnetic field, pressure, and/or lattice strain. For the first time we here show that spin-state transitions can also be induced by an electric field in the case of magnetoelectric materials that display magnetic instabilities. Materials with pure ionic bonding typically possess centrosymmetric structures owing to the minimizing of short-range Coulomb repulsions and they are hence nonferroelectric. The noncentrosymmetry required...

show abstract

Metamagnetism, giant magnetoresistance and magnetocaloric effects in RCo2-based compounds in the vicinity of the Curie temperature

Cited by 186 publications

References 9 publications

Itinerant electron metamagnetism and magnetocaloric effect in Dy(Co,Si)2

Itinerant electron metamagnetism and magnetocaloric effect in Dy(Co,Si)2

CMA's as Magnetocaloric Materials

Magnetic‐Instability‐Induced Giant Magnetoelectric Coupling

Contact Info

Product

Resources

About