Phase separation in amorphous Fe-Zr: Comparison of sputtered and solid-state-reacted films

Hu, Krebs; Webb, DJ; Marshall, A. E.

doi:10.1103/physrevb.35.5392

Cited by 57 publications

(14 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2. The Curie temperatures of the alloys investigated were estimated from the minima of the dM /dT vs T plots, 14 10 (T C ϭ219 K), show good agreement with previously reported data. 9,12 From the present results it can be concluded that a thermally induced reversible magnetic transition occurs for all the samples investigated.…”

supporting

confidence: 68%

See 1 more Smart Citation

Thermoremanence anomaly in Fe-Zr(B,Cu) Invar metallic glasses: Volume expansion induced ferromagnetism

et al. 2000

View full text Add to dashboard Cite

We report the existence of a thermally induced sharp increase of thermoremanence around the Curie temperature of Invar-like Fe-Zr͑B,Cu͒ soft magnetic glasses. Neutron-diffraction measurements indicate that a true enhancement of the average local magnetic moment, rather than only a change in the domain structure, occurs. Such enhancement has been tentatively attributed to the increasing volume expansion that takes place beyond the Curie temperature and reinforces ferromagnetism in some low-density clusters.The origin of the complex magnetic properties of ironrich metallic glasses containing low concentrations of early transition metals ͑Zr,Sc,Hf,Y͒ have attracted considerable interest during more than two decades, giving rise to several controversial microscopic interpretations. [1][2][3][4] In particular Fe x Zr 100Ϫx amorphous alloys with x above 80 at.% rank among the most extensively studied spin system, 5-10 exhibiting weak itinerant ferromagnetism, low-temperature spinglass-like behavior and Invar character.Nowadays it is clear that Invar-like iron-rich Fe x Zr 100Ϫx , as well as Fe-Zr͑B,Cu͒, 12 soft magnetic glasses exhibit: ͑i͒ a sharp increase of the thermal expansion above the Curie temperature, T C , 2,3 ͑ii͒ a large high-field susceptibility, 5 ͑iii͒ a decrease in both the magnetic moment and T C with increasing x, 9 ͑iv͒ a large positive spontaneous volume magnetostriction, 11 ͑v͒ a positive shift in T C with the tensile stress, 12 and a large but negative shift with pressure. 2,3 Moreover, it is well established that, as a consequence of competitive positive and negative interactions, the spontaneous magnetization is low and the effect of the field is to induce local magnetic moment, as pointed out by the high volume magnetostriction at low fields. 11 In addition, due to the sensitivity of the local magnetic moment to the interatomic distances, the spontaneous magnetization is expected to fluctuate with density fluctuations which are always present in amorphous structures. The sign of the magnetic interactions depends on the interatomic distances giving rise to the coexistence of complex magnetic phases and in this way both cluster 13 and frustration 8 microscopic models have been proposed to account for the overall behavior. According to the positive volume magnetostriction experimentally observed, 11 it is accepted that those regions or clusters with lower local density should exhibit the higher local magnetic moment and thus stronger ferromagnetic character. On the other hand, spinglass-like regions with higher density will surround these ferromagnetic clusters so decreasing the average local magnetic moment.In this work we present the highlights of a detailed experimental study regarding the thermoremanence behavior in amorphous Fe-Zr͑B,Cu͒ which confirms the appearance of a reversible magnetic transition that occurs around their Curie points. 10 were produced in the form of ribbons, with approximate thicknesses of 20 m, using the melt spinning technique. The amorphous structure of all the samp...

show abstract

supporting

confidence: 68%

“…10 were produced in the form of ribbons, with approximate thicknesses of 20 m, using the melt spinning technique. The amorphous structure of all the samples was checked by x-ray diffraction and Mössbauer spectroscopy.…”

mentioning

confidence: 99%

Thermoremanence anomaly in Fe-Zr(B,Cu) Invar metallic glasses: Volume expansion induced ferromagnetism

et al. 2000

View full text Add to dashboard Cite

show abstract

“…Several researchers have studied the effect of irradiation and thermal annealing on phase formation in Zr/Fe multilayers, 3-5,8,9,17-35 using CEMS, 5 calorimetry, 34 magnetization, 4 x-ray, resisitivity, RBS, mechanical properties, 11 or TEM. 19 Kiauka and Keune 9 found that the maximum Fe thickness that reacts by solid-state reaction is 2 nm.…”

Section: A Solid-state Reaction In Zr-fe Multilayersmentioning

confidence: 99%

“…[1][2][3][4][5] Metallic multilayers represent a model system to study the kinetics and thermodynamics of phase formation because they can be manufactured at given thicknesses and compositions, and be subjected to thermal annealing or irradiation under precisely controlled conditions. The Zr-Fe system is of particular interest because it can serve as a model system for the solid-state reaction between the late and early transition metals, and because the presence of Fe allows the use of hyperfine and magnetic techniques to complement structural x-ray diffraction techniques in detecting the appearance of new phases.…”

Section: Introductionmentioning

confidence: 99%

Phase formation in Zr–Fe multilayers: Effect of irradiation

Motta

Paesano

Birtcher

et al. 1999

Journal of Applied Physics

View full text Add to dashboard Cite

We have conducted a detailed in situ study of phase formation in Zr-Fe metallic multilayers using irradiation and thermal annealing. Metallic multilayers with near equiatomic and Fe-rich overall compositions and with repetition thicknesses ranging from 7.4 to 33 nm were either irradiated with 300 keV Kr ions at various temperatures ͑from 17 to 623 K͒ or thermally annealed at 773 K while being observed in situ. The kinetics of multilayer reaction were monitored by following the diffraction patterns. For near equiatomic samples, irradiation causes complete amorphization. The dose to amorphization increases in proportion to the square of the wavelength, indicating a process controlled by atomic transport. Amorphization was also achieved by 900 keV electron irradiation at 25 K showing that displacement cascades are not required. The critical dose to amorphization was independent of temperature below room temperature and decreased above room temperature. The activation energy for this second process is 0.17 eV. For the temperature range studied, diffraction from Zr disappears first, indicating that amorphization takes place in the Zr layer by atomic transport of Fe from the Fe layers. These results are consistent with a combination of simple ballistic mixing at low temperature and either simple diffusion or radiation-enhanced diffusion at higher temperatures. Thermal annealing of the equiatomic samples at 773 K produced the same reaction products with slower kinetics. Ion irradiation of Fe-rich samples did not cause complete amorphization and intermetallic compounds Zr 3 Fe and ZrFe 2 were observed in longer wavelength samples. Amorphization of Fe-rich samples was more sluggish, likely because there was competition with formation of other phases. The reaction kinetics were not proportional to square of wavelength for Fe-rich samples, indicating a process that depends on more than atomic transport. Thermal annealing at 773 K of a long wavelength, 57% Fe sample resulted in intermetallic compounds Zr 3 Fe and ZrFe 2 which amorphized during subsequent irradiation. The ease of amorphization of equiatomic samples relative to Fe-rich samples can be explained by a narrower, single minimum free energy curve for the amorphous phase.

show abstract

“…Polycrystalline Fe/Zr multilayers undergo a transition to amorphous state through the process of solid state reaction [1]. For multilayers (Mis) of sufficiently small wavelength of modulation this process plays an important role also in as-deposited films [2].…”

Section: Introductionmentioning

confidence: 99%