scholarly journals Exotic magnetic behaviour and evidence of cluster glass and Griffiths like phase in Heusler alloys Fe2-xMnxCrAl (0 ≤ x ≤ 1)

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kavita Yadav ◽  
Mohit K. Sharma ◽  
Sanjay Singh ◽  
K. Mukherjee
Keyword(s):  
Structural Investigation ◽  
Ac Susceptibility ◽  
Heusler Alloys ◽  
Temperature Response ◽  
Magnetic Ordering ◽  
Magnetic Behaviour ◽  
Magnetic Memory ◽  
X Ray Diffraction ◽  
Systematic Analysis ◽  
Mn Concentration

Abstract We present a detailed study of structural, magnetic and thermodynamic properties of a series of Heusler alloys Fe2-xMnxCrAl (x = 0, 0.25, 0.5, 0.75 and 1). Structural investigation of this series is carried out using high resolution synchrotron X-ray diffraction. Results suggest that with increasing Mn concentration, the L21 structure of Fe2CrAl is destabilized. The DC magnetization results show a decrement in paramagnetic (PM) to ferromagnetic (FM) phase transition temperature (TC) with increasing Mn concentration. From the systematic analysis of magnetic memory effect, heat capacity, time dependent magnetization, and DC field dependent AC susceptibility studies it is observed that, Fe2CrAl exhibits cluster glass(CG)-like transition approximately at 3.9 K (Tf2). The alloys, Fe1.75Mn0.25CrAl and Fe1.5Mn0.5CrAl exhibit double CG-like transitions near Tf1 ~ 22 K, Tf2 ~ 4.2 K and Tf1 ~ 30.4 K, Tf2 ~ 9.5 K respectively, however, in Fe1.25Mn0.75CrAl, a single CG-like transition is noted at Tf2 ~ 11.5 K below TC. Interestingly, FeMnCrAl shows the absence of long ranged magnetic ordering and this alloy undergoes three CG-like transitions at ~22 K (Tf*), 16.6 K (Tf1) and 11 K (Tf2). At high temperatures, a detailed analysis of temperature response of inverse DC susceptibility clearly reveals the observation of Griffiths phase (GP) above 300 K (T*) in Fe2CrAl and this phase persists with Mn concentration with a decrement in T*.

Superconductivity and Magnetic Ordering of Pr in CaLa1-xPrxBaCu3O7 System

1997 ◽  
Vol 11 (07) ◽  
pp. 323-331 ◽  
Author(s):  
V. P. S. Awana ◽  
Rajvir Singh ◽  
D. A. Landinez Tellez ◽  
J. M. Ferreira ◽  
J. Albino Aguiar ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Normal State ◽  
Ac Susceptibility ◽  
Magnetic Ordering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Antiferromagnetic Ordering ◽  
Peak Intensity ◽  
Heat Capacity Measurements ◽  
A Minor

We present the results of superconductivity, normal state magnetic susceptibility and heat capacity measurements on the tetragonal CaLa 1-x Pr x BaCu 3 O 7 compound. Ac susceptibility measurements show that the transition temperature T c of the unsubstituted sample decreases with an increase in the Pr concentration. Normal state dc magnetic susceptibility measurements performed in an applied field of 0.5 T show a Curie–Weiss behaviour in terms of the paramagnetic moment of Pr. The effective paramagnetic moment of Pr appears to be intermediate between those of the free Pr 3+ and Pr 4+ ions. For the nonsuperconducting samples i.e., x = 0.70 and 1.0, we observe an antiferromagnetic ordering temperature T N of nearly 4 K and 8 K respectively. The X-ray diffraction results show that the CaPrBaCu 3 O 7 compound is free from other phases, having a minor (less than 8%, in terms of peak intensity) impurity phase. The lower T N (8 K) of PrBaCaCu 3 O 7 as compared to the known antiferromagnetic ordering temperature of 17 K for PrBa 2 Cu 3 O 7 indicates a less deleterious effect of Pr in the present case.

Evolution of Magnetic Ordering in Spinel Oxide System: Mn1.5(1-x)Ti0.5(1-x)Fe(1+ 1.5x)Li(0.5)xO4

2013 ◽  
Vol 209 ◽  
pp. 27-30
Author(s):  
Vaishali P. Joshi ◽  
Ashish R. Tanna ◽  
Kalpesh H. Jani ◽  
H.H. Joshi
Keyword(s):  
Ac Susceptibility ◽  
Magnetic Hyperfine Field ◽  
Magnetic Ordering ◽  
Oxide System ◽  
Spinel Oxide ◽  
X Ray Diffraction ◽  
Ceramic Method ◽  
X Ray ◽  
Structural And Magnetic Properties ◽  
Temperature And Growth

Six compositions: x = 0.0 to 0.5 of the spinel system Mn1.5(1-x)Ti0.5(1-x)Fe(1+ 1.5x) Li(0.5)x O4 are synthesized by ceramic method. The structural and magnetic properties are studied by means of X-ray diffraction, AC susceptibility, Magnetization and Mossbauer spectroscopy. The study reveals the significance of FeA-O-FeB magnetic linkages in evolution of long range magnetic ordering through rise in Curie temperature and growth of magnetic hyperfine field with increase in x.

STRUCTURAL AND MAGNETOELASTIC PROPERTIES OF Y3Fe27.2Cr1.8 AND Ce3Fe25Cr4 FERROMAGNETIC COMPOUNDS

2011 ◽  
Vol 25 (24) ◽  
pp. 1949-1961 ◽  
Author(s):  
N. TAJABOR ◽  
A. GHOLIZADEH ◽  
M. BEHDANI ◽  
D. SANAVI KHOSHNOUD ◽  
H. SALAMATI ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Linear Thermal Expansion Coefficient ◽  
Ac Susceptibility ◽  
Linear Thermal Expansion ◽  
Magnetic Ordering ◽  
Anisotropy Field ◽  
Magnetic Phase Transitions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Magnetoelastic Properties

The structural and magnetoelastic properties of polycrystalline samples of Y 3 Fe 27.2 Cr 1.8 and Ce 3 Fe 25 Cr 4 intermetallic compounds are investigated by means of X-ray diffraction, thermomagnetic, thermal expansion and magnetostriction measurements in the temperature range of 77–500 K under applied magnetic fields up to 1.5 T. The well defined anomalies observed in the linear thermal expansion coefficient curves are associated with the magnetic phase transitions and presence of small amounts of 1:12 phase in the Ce 3 Fe 25 Cr 4 sample; the latter is also confirmed by AC susceptibility measurements. For Y 3 Fe 27.2 Cr 1.8, saturation behavior is observed in the anisotropic magnetostriction isotherms near the magnetic ordering temperature (TC), whereas for Ce 3 Fe 25 Cr 4 compound, saturation starts well below TC. The additional anomalies observed in the volume magnetostriction isotherms of both compounds are explained based on the anisotropy field in the a–b plane and along the c-axis of the unit cell.

Investigation of Magnetic Behaviour of Mechanical Activation Derived Multiferroic BiFeO3

2007 ◽  
Vol 997 ◽  
Author(s):  
Ashish Garg ◽  
Hari Kishan Thota ◽  
Brajesh Pandey ◽  
H C Verma
Keyword(s):  
Mechanical Activation ◽  
Magnetic Measurements ◽  
Magnetic Ordering ◽  
Magnetic Behavior ◽  
Magnetic Behaviour ◽  
X Ray Diffraction ◽  
Sample Heat ◽  
Heat Treated ◽  
Multiferroic Bifeo ◽  
Multiferroic Bifeo3

AbstractHere we report on the synthesis of multiferroic BiFeO3 ceramics by mechanical activation and detailed investigation into its magnetic behavior. The mechanically milled ceramic was calcined at temperatures up to 800°C. X-ray diffraction studies show only the pure BiFeO3 phase forms at 700°C. Vibrating sample magnetometer (VSM) measurements were carried out up to 1.5 Tesla and the results show a weak magnetic ordering in the ceramics. The magnetic measurements were also done on the samples heat treated under various cooling conditions. VSM measurements showed pronounced effect of cooling on the Magnetization vs Field curves. Mössbauer measurements show that short range Fe2O3 ordering is still present in the sample that goes undetected by XRD. This component decreases as the calcination temperature is increased. The nature of magnetic ordering improves upon heating from 600 to 700°C, also suggested by pure BiFeO3 phase formation at 700°C. Magnetization vs Temperature measurements conducted on the sample heat treated at 700°C for 1hr followed by cooling in air show an antiferromagnetic transition at ∼370°C.

scholarly journals Emergent long-range magnetic order in ultrathin (111)-oriented LaNiO3 films

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Margaret M. Kane ◽  
Arturas Vailionis ◽  
Lauren J. Riddiford ◽  
Apurva Mehta ◽  
Alpha T. N’Diaye ◽  
...  
Keyword(s):  
Long Range ◽  
Degrees Of Freedom ◽  
Magnetic Order ◽  
Magnetic Ordering ◽  
Anomalous Hall Effect ◽  
X Ray Diffraction ◽  
X Ray ◽  
Range Magnetic Order ◽  
Film Substrate ◽  
Long Range Magnetic Order

AbstractThe emergence of ferromagnetism in materials where the bulk phase does not show any magnetic order demonstrates that atomically precise films can stabilize distinct ground states and expands the phase space for the discovery of materials. Here, the emergence of long-range magnetic order is reported in ultrathin (111) LaNiO3 (LNO) films, where bulk LNO is paramagnetic, and the origins of this phase are explained. Transport and structural studies of LNO(111) films indicate that NiO6 octahedral distortions stabilize a magnetic insulating phase at the film/substrate interface and result in a thickness-dependent metal–insulator transition at t = 8 unit cells. Away from this interface, distortions relax and bulk-like conduction is regained. Synchrotron x-ray diffraction and dynamical x-ray diffraction simulations confirm a corresponding out-of-plane unit-cell expansion at the interface of all films. X-ray absorption spectroscopy reveals that distortion stabilizes an increased concentration of Ni2+ ions. Evidence of long-range magnetic order is found in anomalous Hall effect and magnetoresistance measurements, likely due to ferromagnetic superexchange interactions among Ni2+–Ni3+ ions. Together, these results indicate that long-range magnetic ordering and metallicity in LNO(111) films emerges from a balance among the spin, charge, lattice, and orbital degrees of freedom.

X-Ray Diffraction Study of Rare Earth Epitaxial Structures Grown by MBE onto (111) GaAs

1989 ◽  
Vol 151 ◽  
Author(s):  
W. R. Bennett ◽  
R. F. C. Farrow ◽  
S. S. P. Parkin ◽  
E. E. Marinero
Keyword(s):  
Rare Earth ◽  
Molecular Beam Epitaxy ◽  
Rare Earth Metal ◽  
Molecular Beam ◽  
Earth Metal ◽  
Magnetic Ordering ◽  
Metal Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Strain Components

ABSTRACTWe report on the new epitaxial system LaF3/Er/Dy/Er/LaF3/GaAs (111) grown by molecular beam epitaxy. X-ray diffraction studies have been used to determine the epitaxial relationships between the rare earths, the LaF3 and the substrate. Further studies of symmetric and asymmetric reflections yielded the in-plane and perpendicular strain components of the rare earth layers. Such systems may be used to probe the effects of magnetoelastic interactions and dimensionality on magnetic ordering in rare earth metal films and multilayers.

Magnetic ordering in relaxor ferroelectric (1 − x)Pb(Fe2/3W1/3)O3–xPbTiO3 single crystals

2007 ◽  
Vol 22 (8) ◽  
pp. 2116-2124 ◽  
Author(s):  
Li Feng ◽  
Haiyan Guo ◽  
Zuo-Guang Ye
Keyword(s):  
Single Crystals ◽  
Magnetic Measurements ◽  
Ferroelectric Properties ◽  
Magnetic Ordering ◽  
Magnetic Behavior ◽  
Relaxor Ferroelectric ◽  
X Ray Diffraction ◽  
Ferroelectric State ◽  
Temperature Changes ◽  
Temperature Solution

Single crystals of the perovskite solid solution (1 − x)Pb(Fe2/3W1/3)O3–xPbTiO3, with x = 0, 0.07, 0.27, and 0.75, have been synthesized by the high-temperature solution growth using PbO as flux and characterized by x-ray diffraction and dielectric and magnetic measurements. The crystal structure at room temperature changes from a pseudocubic to a tetragonal phase with the PbTiO3 (PT) content increasing to x ⩾ 0.27. As the amount of PT increases, the relaxor ferroelectric behavior of Pb(Fe2/3W1/3)O3 (PFW) is transformed toward a normal ferroelectric state with sharp and nondispersive peaks of dielectric permittivity at TC. Two types of magnetic orderings are observed on the temperature dependence of the magnetization in the crystals with x ⩽ 0.27. This behavior is explained based on the relationships among the magnetic ordering, perovskite structure, composition, and relaxor ferroelectric properties. Furthermore, the macroscopic magnetization of the system was measured under the application of a magnetic field, which demonstrates different magnetic behavior associated with the weakly ferromagnetic, antiferromagnetic, and paramagnetic ordering in the temperature range of 2 to 390 K. Interestingly, the low-temperature ferromagnetism is enhanced by the addition of ferroelectric PT up to x = 0.27.

scholarly journals Synthesis, Crystal Structure and Magnetic Properties of Bixbyite-type Vanadium Oxide Nitrides

2009 ◽  
Vol 64 (3) ◽  
pp. 281-286 ◽  
Author(s):  
Suliman Nakhal ◽  
Wilfried Hermes ◽  
Thorsten Ressler ◽  
Rainer Pöttgen ◽  
Martin Lerch
Keyword(s):  
Crystal Structure ◽  
Vanadium Oxide ◽  
Magnetic Ordering ◽  
Vanadium Oxides ◽  
Detectable Amount ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vanadium Sulfide ◽  
Structure Result ◽  
X Ray Absorption

Ammonolysis of vanadium sulfide leads to the formation of bixbyite-type vanadium oxide nitrides. Small amounts of nitrogen incorporated in the structure result in the stabilization of the bixbyite type not known for vanadium oxides. The crystal structure was investigated using X-ray diffraction and X-ray absorption spectroscopy. At temperatures above 550 °C the powders decompose to corundumtype V2O3 containing no detectable amount of nitrogen. Below 39 K magnetic ordering is observed.

Structure, Magnetic Properties and Hyperfine Parameters of Nd-Substituted Ni-Fe-Ga Heusler Alloys

MRS Advances ◽  
2017 ◽  
Vol 2 (25) ◽  
pp. 1341-1346
Author(s):  
Monica Sorescu ◽  
Felicia Tolea ◽  
Mihaela Valeanu ◽  
Mihaela Sofronie
Keyword(s):  
Melt Spinning ◽  
Magnetic Measurements ◽  
Heusler Alloys ◽  
Hyperfine Magnetic Field ◽  
Rapid Quenching ◽  
Linear Least Squares ◽  
X Ray Diffraction ◽  
Hyperfine Parameters ◽  
X Ray ◽  
Field Distributions

ABSTRACTSamples of Ni57-xNdxFe18Ga25 with x=2 and 4 were prepared in ribbon form by rapid quenching via melt spinning route. The samples were analyzed by X-ray diffraction (XRD), magnetic measurements and Mössbauer spectroscopy, both in the as-quenched form and after thermal annealing at 900 oC for 2 min and 400 °C for 2 hours. For x=2 the Nd atoms are completely dissolved in the Ni-Fe-Ga matrix, while for x=4 the additional occurrence of the secondary 2:17 phase could be resolved. These findings were supported by the analysis of hyperfine magnetic field distributions obtained from the non-linear least-squares fitting of the Mössbauer spectra.

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