Synthesis and Non-isothermal Carbothermic Reduction of FeTiO<Subscript>3</Subscript>-Fe<Subscript>2</Subscript>O<Subscript>3</Subscript> Solid Solution Systems

To investigate the carbothermic reduction behaviors of xFeTiO₃·(1 ? x)Fe₂O₃ solid solutions, the solid solutions with different x values were synthesized and used in the corresponding reactions. With an increase in x, the temperature pertaining to the onset of carbothermic reduction increased, while the rate of reduction of the solid solutions, α, decreased. The lattice parameters calculated from XRD patterns indicated that the solid solution with a higher x led to a larger lattice distortion. The non-isothermal kinetics were calculated, and an average activation energy E value of 3.0 × 10² kJ/mol was obtained.     

The Interface of TiB<Subscript>2</Subscript> and Al<Subscript>3</Subscript>Ti in Molten Aluminum

In the grain refinement of aluminum, Al₃Ti and TiB₂ particles are introduced to reduce the casting grain size down to 200 micrometer level, which makes cold working possible. The particles are brought in by the addition of Al-Ti-B-type master alloys. It is generally believed that TiB₂ particles are stable and nucleate α-Al grains in solidification in the presence of titanium in solution from the dissolution of Al₃Ti particles in the master alloys. The titanium in solution either forms Al₃Ti layers on the surface of TiB₂ particles to promote the nucleation of α-Al grains or remains as solute to restrict the growth of α-Al grains in solidification. However, a consensus on a grain refinement mechanism is still to be reached due to the lack of direct observation of the three phases in castings. This paper presents finding of the TiB₂/Al₃Ti interfaces in an Al-Ti-B master alloy. It demonstrates a strong epitaxial growth of Al₃Ti on the surface of TiB₂ particles, a sign of the formation of an Al₃Ti layer on the surface of TiB₂ particles in grain refinement practice. The Al₃Ti layer has a crystal coherency with α-Al and hence offers a substrate for heterogeneous nucleation of α-Al grains. However, the layer must be dynamic to avoid the formation of compounded Al₃Ti and TiB₂ particles leading to the loss of efficiency in grain refinement.     

Peculiarities of the technology and physicomechanical properties of a laminated Al<Subscript>2</Subscript>O<Subscript>3</Subscript>-Al cermet

A technological approach permitting one to obtain laminated Al₂O₃-Al cermet is considered. The industrial PAP-2 powder with laminated particles served as the starting crude. The powder billets were obtained by compaction under pressure (P) from 100 to 1000 MPa and thermally treated in air by heating in the furnace to 600°C. It is established that either the solid-phase sintering or reaction sintering of the billets in the mode of filtration combustion can be achieved depending on the value of P. In the produced composite, the content of the oxide phase varies from 5 to 40%, while the density and strength upon bending vary in the limits 2.53–2.00 g/cm³ and 330-98 MPa, respectively. The laminated structure of the material is retained after thermal aging in air at t= 600°C for no less than 1000 h.     

Separation of Fine Al<Subscript>2</Subscript>O<Subscript>3</Subscript> Inclusion from Liquid Steel with Super Gravity

An innovative approach of super gravity was proposed to separate fine Al₂O₃ inclusions from liquid steel in this study. To investigate the removal behaviors of inclusions, the effects of different gravity coefficients and time on separating the inclusions were studied. The results show that a large amount of Al₂O₃ inclusions gathered at the top of the sample obtained by super gravity, whereas there were almost no inclusions appearing at the bottom. The volume fraction and number density of inclusions presented a gradient distribution along the direction of the super gravity, which became steeper with increasing gravity coefficient and separating time. As a result of the collision between inclusions, a large amount of inclusions aggregated and grew during the moving process, which further decreased the removal time. The experimental required removal time of inclusions is close to the theoretical values calculated by Stokes law under gravity coefficient G ≤ 80, t ≤ 15 minutes, and the small deviation may be because the inclusion particles are not truly spherical. Under the condition of gravity coefficient G = 80, t = 15 minutes, the total oxygen content at the bottom of the sample (position of 5 cm) is only 8.4 ppm, and the removal rate is up to 95.6 pct compared with that under normal gravity.     

Effect of Slag Composition on the Crystallization Kinetics of Synthetic CaO-SiO<Subscript>2</Subscript>-Al<Subscript>2</Subscript>O<Subscript>3</Subscript>-MgO Slags

The crystallization kinetics of CaO-SiO₂-Al₂O₃-MgO (CSAM) slags was studied with the aid of single hot thermocouple technique (SHTT). Kinetic parameters such as the Avrami exponent (n), rate coefficient (K), and effective activation energy of crystallization (E _A ) were obtained by kinetic analysis of data obtained from in situ observation of glassy to crystalline transformation and image analysis. Also, the dependence of nucleation and growth rates of crystalline phases were quantified as a function of time, temperature, and slag basicity. Together with the observations of crystallization front, they facilitated establishing the dominant mechanisms of crystallization. In an attempt to predict crystallization rate under non-isothermal conditions, a mathematical model was developed that employs the rate data of isothermal transformation. The model was validated by reproducing an experimental continuous cooling transformation diagram purely from isothermal data.     

Amphoteric behavior of alumina in viscous flow and structure of CaO-SiO<Subscript>2</Subscript> (-MgO)-Al<Subscript>2</Subscript>O<Subscript>3</Subscript> slags

The viscosity of CaO-SiO₂ (-MgO)-Al₂O₃ slags was measured to clarify the effects of Al₂O₃ and MgO on the structure and viscous flow of molten slags at high temperatures. Furthermore, the infrared spectra of the quenched slags were analyzed to understand the structural role of Al₂O₃ in the polymerization or depolymerization of silicate network. The Al₂O₃ behaves as an amphoteric oxide with the composition of slags; that is, the alumina behaves as a network former up to about 10 mass pct Al₂O₃, while it acts as a network modifier, in parts, in the composition greater than 10 mass pct Al₂O₃. This amphoteric role of Al₂O₃ in the viscous flow of molten slags at the Newtonian flow region was diminished by the coexistence of MgO. The effect of Al₂O₃ on the viscosity increase can be understood based on an increase in the degree of polymerization (DOP) by the incorporation of the [AlO₄]-tetrahedra into the [SiO₄]-tetrahedral units, and this was confirmed by the infrared (IR) spectra of the quenched slags. The influence of alumina on the viscosity decrease can be explained on the basis of a decrease in the DOP by the increase in the relative fraction of the [AlO₆]-octahedral units. The relative intensity of the IR bands for the [SiO₄]-tetrahedra with low NBO/Si decreased, while that of the IR bands for [SiO₄]-tetrahedra with high NBO/Si increased with increasing Al₂O₃ content greater than the critical point, i.e., about 10 mass pct in the present systems. The variations of the activity coefficient of slag components with composition indirectly supported those of viscosity and structure of the aluminosilicate melts.     

Development of Low-Fluoride Slag for Electroslag Remelting: Role of Li<Subscript>2</Subscript>O on the Viscosity and Structure of the Slag

The effect of the substitution of CaF₂ with Li₂O on the viscosity and structure of low-fluoride CaF₂-CaO-Al₂O₃-MgO slag was studied with an aim to develop low-fluoride slag for electroslag remelting. Increasing Li₂O addition up to 4.5 mass pct was observed to significantly reduce the slag viscosity monotonically. Increasing temperature significantly lowered the viscosity of slag, whereas this influence is less effective with increasing Li₂O content especially above 3.5 mass pct. The activation energy for viscous flow decreases with increasing Li₂O content. The polymerization degree of aluminate networks decreased with increasing Li₂O content, as demonstrated by Raman analysis. The dominant structural unit in [AlO₄]^5?-tetrahedral network is \( {\text{Q}}_{\text{Al}}^{4} \). The amount of symmetric Al-O⁰ stretching vibrations significantly decreased with increasing Li₂O content. The relative fraction of \( {\text{Q}}_{\text{Al}}^{4} \) in the [AlO₄]^5?-tetrahedral units shows a decreasing trend, whereas \( {\text{Q}}_{\text{Al}}^{2} \) increases with the increase in Li₂O content accordingly. The change in slag viscosity with chemistry variation agrees well with the changes in slag structural units.     

Suppression of Martensitic Transformation in Co<Subscript>2</Subscript>Cr(Ga,Si) Heusler Alloys by Thermal Cycling

We have investigated the influence of thermal cycles on martensitic transformation of a Co₂Cr(Ga,Si) ferromagnetic Heusler alloy. The as-quenched specimen exhibits successive L2₁(L)–D0₂₂–L2₁(H) martensitic transformation in the cooling process, which is known as reentrant martensitic transformation. However, heating to 800 K (527 °C) for reverse D0₂₂–L2₁ transformation with a rate of 10 K/min (10 °C/min) stabilizes the parent phase, meaning that the martensitic transformation is suppressed by the thermal cycles. We found precipitate after thermal cycles, and it will be the reason for the stabilization of parent phase.     

Effect of Al<Subscript>2</Subscript>O<Subscript>3</Subscript> Concentration on Density and Structure of (CaO-SiO<Subscript>2</Subscript>)-xAl<Subscript>2</Subscript>O<Subscript>3</Subscript> Slag

The effect of Al₂O₃ concentration on the density and structure of CaO-SiO₂-Al₂O₃ slag was investigated at multiple Al₂O₃ mole percentages and at a fixed CaO/SiO₂ ratio of 1. The experiments were conducted in the temperature range of 2154 K to 2423 K (1881 °C to 2150 °C) using the aerodynamic levitation technique. In order to understand the relationship between density and structure, structural analysis of the silicate melts was carried out using Raman spectroscopy. The density of each slag sample investigated in this study decreased linearly with increasing temperature. When the Al₂O₃ content was less than 15 mole pct, density decreased with increasing Al₂O₃ content due to the coupling of Si (Al), whereas above 20 mole pct density of the slag increased due to the role of Al³⁺ ion as a network modifier.     

Structure and phase composition of alloys of the Al-Ce-Cu system in the region of the Al-Al<Subscript>8</Subscript>CeCu<Subscript>4</Subscript> quasi-binary join

Phase diagram of the Al-Cu-Ce system is investigated in the region of the quasi-binary join Al-Al₈CeCu₄. The parameter of the eutectic reaction L → (Al) + CeCu₄Al₈ are found: T = 610°C; composition 14% Cu and 7% Ce. This eutectic has a dispersed structure, and the ternary compounds, which is involved in the eutectic, is capable to fragmentation and spheroidism in the course of heating starting from 540°C. It is shown that the region of optimal compositions of alloys based on the eutectic (Al) + CeCu₄Al₈ lies in narrow limits. This is caused by the fact that an abrupt decrease of the solidus and, as a consequence, significant broadening of the crystallization range occurs at a relatively small deviation from the ratio Cu: Ce = 2.     

Synthesis of Al-Zr Alloys <Emphasis Type="Italic">Via</Emphasis> ZrO<Subscript>2</Subscript> Aluminum-Thermal Reduction in KF-AlF<Subscript>3</Subscript>-Based Melts

Physical–chemical investigations of KF-AlF₃ melts were carried out in order to develop the scientific basis of the technology for Al-Zr alloy synthesis. The possibility of Al-Zr alloy synthesis via the aluminum-thermal method was shown. The liquidus temperatures of KF-AlF₃ and KF-NaF-AlF₃ melts with additions of Al₂O₃ and ZrO₂ were determined using the thermal analysis method in the temperature range from 873 K to 1173 K (600 °C to 900 °C). The dependency of the solubility of ZrO₂ in KF-AlF₃ and KF-NaF-AlF₃ melts on Al₂O₃ concentration was measured.     

Microstructure and Properties of Fe<Subscript>3</Subscript>Al-Fe<Subscript>3</Subscript>AlC<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> Composite Prepared by Reactive Liquid Processing

A Fe₃Al-Fe₃AlC _x composite was prepared using reactive liquid processing (RLP) through controlled mixture of carbon steel and aluminum in the liquid state. The microstructure and phases of the composite were assessed using X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, optical microscopy, and differential scanning calorimetry. In addition, the density, hardness, microhardness, and elastic modulus were evaluated. The Fe₃Al-Fe₃AlC _x composite consisted of 65 vol pct Fe₃Al and 35 vol pct Fe₃AlC _x (κ). The κ phase contained 10.62 at. pct C, resulting in the stoichiometry Fe₃AlC_0.475. The elastic modulus of the Fe₃Al-Fe₃AlC_0.475 composite followed the rule of mixtures. The RLP technique was shown to be capable of producing Fe₃Al-Fe₃AlC_0.475 with a microstructure and properties similar to those achieved using other processing techniques reported in the literature.     

Structure and magnetic properties of the Nd<Subscript>9.5</Subscript>Fe<Subscript>84.5</Subscript>B<Subscript>6</Subscript> alloy subjected to severe plastic deformation and annealing

The effect of severe plastic deformation (SPD) by torsion and subsequent annealing on the structure and magnetic properties of the cast Nd_9.5Fe_84.5B₆ alloy is studied. SPD by torsion is shown to lead to partial amorphization of the Nd₂Fe¹⁴B phase and the precipitation of α-Fe; subsequent annealing results in the crystallization of the amorphous phase and the formation of a nanocomposite Nd₂Fe₁₄B/α-Fe structure. After SPD by torsion at 20 revolutions and annealing at 873 K, the (101) texture is formed; in this case, the coercive force is H _c = 360 kA/m and the maximum energy product is (BH) _max = 166 kJ/m3. The residual magnetization and the squareness ratio of the hysteretic loop of the textured alloy decrease as the ambient temperature decreases.     

Rare-earth metals (REMs) in nickel aluminide-based alloys: I. Physicochemical laws of interaction in the Ni-Al-REM and Ni<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Al<Subscript><Emphasis Type="Italic">y</Emphasis></Subscript>-REM-AE (alloying element) systems

The data on the Ni-Al-R (R = REM Sc, Y, La, lanthanides) binary and ternary systems and the interactions of three rare-earth metals (yttrium, lanthanum, cerium) with the main alloying elements (Ti (Zr, Hf), Cr (Mo, W) that are introduced into Ni₃Al-based VKNA alloys are analyzed. The binary aluminides of REMs in the Ni-Al-R ternary systems are shown to be in equilibrium with neither NiAl nor Ni₃Al. The solid solution of aluminum in RNi₅, which penetrates deep into these ternary systems, is the most stable phase in equilibrium with Ni₃Al. In the NiAl (Ni₃Al)-AE-R systems, REM precipitation (segregation) on various defects and interfaces in nickel aluminides is likely to be the most probable, and REMs are thought to interact with the most active impurities in real alloys (C, O, N), since REMs have a large atomic radius and, thus, are virtually undissolved in nickel, aluminum, and nickel aluminides.     

Composition and Mobility of Ionic Ensembles in Slags for Steel Refining in the Ladle–Furnace Unit

High-lime synthetic slags for refining steels in the ladle–furnace unit are investigated. The content of the slag mixtures is as follows: 60 wt % CaO, 7 and 8 wt % MgO, 7–23 wt % Al₂O₃, and 9–18 wt % SiO₂, with additions of 8 wt % CaF₃ and 5–15 wt % Na₂O. Polymer theory is used to calculate the composition of the anionic subsystem in the slag melts. The log-mean polymerization constants K _p ^* for multicomponent melts are calculated from the known polymerization constants in binary systems. It is found that K _p ^* ≈ 10^–3–10^–2 in the range 1500–1600°C. In that range, the melt’s degree of polymerization is 3 × 10^–4–8 × 10^–3. In the most polymerized melt, the ionic content of the dimers Si₂O ₇ ^6- and Al₂O ₇ ^8- is no more than 0.1 and 1.5% of the values for the corresponding monomers. Therefore, we assume, with an error of about 2%, that the structural units of the anionic subsystem are monomers AlO ₄ ^5- and SiO ₄ ^4- simple O^2– and F^– ions (slag 7). The cationic subsystem consists of Ca²⁺, Mg²⁺, Na⁺, and Al³⁺ ions in octahedral coordination with oxygen (less than 3% of all the Al atoms). In all the melts, the concentrations of free oxygen ions O^2– and Ca²⁺ ions are similar. In half the cases, the content of O^2– ions is greater than the content of Ca²⁺ ions. The mean mobility U and self-diffusion coefficient D for all the cations are calculated from data for the electrical conductivity and the density. With increase in temperature from 1500 to 1600°C, U and D increase by 50 and 60%, respectively, in all the slags. With increase in the mutual substitution of the components in the slag mixtures M = n(Na₂O, CaF₂)/n(Al₂O₃ + SiO₂), mol/mol, at 1600°C, U increases from 1.14 × 10^–8 to 1.46 × 10^–8 m²/(V s) for slags 1–6 (0 ≤ M ≤ 1.1) and from 1.01 × 10^–8 to 1.66 × 10^–8 m²/(V s) for slags 7–10 (0.25 ≤ M ≤ 0.65). Correspondingly, D increases from 9.2 × 10^–10 to 12.8 × 10^–10 m²/s for slags 1–6 and from 8.2 × 10^–10 to 14.3 × 10^–10 m²/s for slags 7–10. The temperature dependence of U and D may be approximated by an Arrhenius equation with activation energies E _U and E _D . With increase in M in the given ranges, E _U declines from 146 to 100 kJ/mol (slags 1–6) and from 124.5 to 109 kJ/mol (slags 7–10). Likewise, E _D declines from 159 to 116.5 kJ/mol (slags 1–6) and from 139.5 to 124 kJ/mol (slags 7–10). The mean values of E _U and E _D correlate with the mean distance between the cations in the melts. On the basis of the proposed alternative model of the conductivity, the O^2– ions may also transfer electric charge. Preliminary estimates show that the oxygen transport number at 1600°C may exceed 0.1 in some slags.     

Relationship between structure and viscosity of CaO–SiO2–MgO–30.00 wt-%Al2O3 slag by molecular dynamics simulation with FT-IR and Raman spectroscopy

Structure of CaO–SiO₂–MgO–30.00?wt-%Al₂O₃ slag was investigated using molecular dynamics simulation at 1873?K, and viscosities with different basicities were measured for quantitatively studying the relationship between structure and viscosity. With the increase of basicity, the three-dimensional networks formed by Si and Al are depolymerised, which is consistent with the analysis using FT-IR and Raman spectroscopy. Additionally, FT-IR analysis shows a dampening of [Al–O–Si] trough, indicating a decrease in the linkage between [SiO₄] and [AlO₄]. Increasing the basicity results in that the BO decreases rapidly, while NBO increases from 32.75% up to 50.23%, which leads to the decrease of viscosity. Variations of CN_Al–O and Al–O–Al indicate that Al₂O₃ prefers to form complicated unit, and Al₂O₃ within this slag should act as a network former. Calculated activation energies of samples A11–A14 are 212, 186, 168 and 161?kJ?mol^?1, respectively. Variation of viscosity linearly depends on Q⁴, and a strong linear relationship could also be found between viscosity and NBO/T. However, the variation of activation energy mainly depends on Q⁴(Si) comparing with Q⁴(Al), Q⁴(Si?+?Al) or NBO/T.     

Distribution Ratios of Phosphorus Between CaO-FeO-SiO<Subscript>2</Subscript>-Al<Subscript>2</Subscript>O<Subscript>3</Subscript>/Na<Subscript>2</Subscript>O/TiO<Subscript>2</Subscript> Slags and Carbon-Saturated Iron

In order to effectively enhance the efficiency of dephosphorization, the distribution ratios of phosphorus between CaO-FeO-SiO₂-Al₂O₃/Na₂O/TiO₂ slags and carbon-saturated iron (\( L_{\text{P}}^{\text{Fe-C}} \)) were examined through laboratory experiments in this study, along with the effects of different influencing factors such as the temperature and concentrations of the various slag components. Thermodynamic simulations showed that, with the addition of Na₂O and Al₂O₃, the liquid areas of the CaO-FeO-SiO₂ slag are enlarged significantly, with Al₂O₃ and Na₂O acting as fluxes when added to the slag in the appropriate concentrations. The experimental data suggested that \( L_{\text{P}}^{\text{Fe-C}} \) increases with an increase in the binary basicity of the slag, with the basicity having a greater effect than the temperature and FeO content; \( L_{\text{P}}^{\text{Fe-C}} \) increases with an increase in the Na₂O content and decrease in the Al₂O₃ content. In contrast to the case for the dephosphorization of molten steel, for the hot-metal dephosphorization process investigated in this study, the FeO content of the slag had a smaller effect on \( L_{\text{P}}^{\text{Fe-C}} \) than did the other factors such as the temperature and slag basicity. Based on the experimental data, by using regression analysis, \( \log L_{\text{P}}^{\text{Fe-C}} \) could be expressed as a function of the temperature and the slag component concentrations as follows:

$$ \begin{aligned} \log L_{\text{P}}^{\text{Fe-C}} & = 0.059({\text{pct}}\;{\text{CaO}}) + 1.583\log ({\text{TFe}}) - 0.052\left( {{\text{pct}}\;{\text{SiO}}_{2} } \right) - 0.014\left( {{\text{pct}}\;{\text{Al}}_{2} {\text{O}}_{3} } \right) \\ \, & \quad + 0.142\left( {{\text{pct}}\;{\text{Na}}_{2} {\text{O}}} \right) - 0.003\left( {{\text{pct}}\;{\text{TiO}}_{2} } \right) + 0.049\left( {{\text{pct}}\;{\text{P}}_{2} {\text{O}}_{5} } \right) + \frac{13{,}527}{T} - 9.87. \\ \end{aligned} $$

     

Density Measurements of Low Silica CaO-SiO<Subscript>2</Subscript>-Al<Subscript>2</Subscript>O<Subscript>3</Subscript> Slags

Density measurements of a low-silica CaO-SiO₂-Al₂O₃ system were carried out using the Archimedes principle. A Pt 30 pct Rh bob and wire arrangement was used for this purpose. The results obtained were in good agreement with those obtained from the model developed in the current group as well as with other results reported earlier. The density for the CaO-SiO₂ and the CaO-Al₂O₃ binary slag systems also was estimated from the ternary values. The extrapolation of density values for high-silica systems also showed good agreement with previous works. An estimation for the density value of CaO was made from the current experimental data. The density decrease at high temperatures was interpreted based on the silicate structure. As the mole percent of SiO₂ was below the 33 pct required for the orthosilicate composition, discrete \textSiO₄^{4 -} {\text{SiO}}_{4}^{4 - } tetrahedral units in the silicate melt would exist along with O^2– ions. The change in melt expansivity may be attributed to the ionic expansions in the order of

Self-propagating high-temperature synthesis of ceramic materials based on the M<Subscript><Emphasis Type="Italic">n</Emphasis> + 1</Subscript>AX<Subscript><Emphasis Type="Italic">n</Emphasis></Subscript> phases in the Ti-Cr-Al-C system

Compact ceramic materials based on the M_{n + 1}AX _n phases in the Ti-Cr-Al-C system are produced by forced self-propagating high-temperature synthesis (SHS) compaction. The mechanisms of the structure and phase formation in synthetic products, as well as the combustion macrokinetics of the SHS mixture, are studied. Complex investigations of the structure, phase composition, and physical and mechanical properties of new Ti_{2 ? x} Cr _x AlC ceramic materials synthesized at different charging parameters (x = 0, 0.5, 1, 1.5, and 2) are performed. The highest content (96–98%) of the M_{n + 1}AX _n phase in the composition of synthetic products is found to be in samples where just one of the host elements (titanium (x = 0) or chromium (x = 2)) is present. The produced materials have a high heat resistance, and the increase in the chromium concentration is favorable to an appreciable growth in resistance to high-temperature oxidation.     

Crystal and Electronic Study of Neodymium-Substituted CuFeO<Subscript>2</Subscript> Oxide

Neodymium-substituted CuFeO₂ samples were investigated according to their crystal and electronic properties via the general formula Nd _x Cu_1?x FeO₂. The crystal structure analysis results revealed polycrystalline formations in the sample and a change in crystalline sizes with the substituted heavy fermion “Nd.” Increasing the Nd amount in the sample was determined to cause a disturbance on the Cu-Fe planes that supports the formation of crystal structures with low crystal symmetries such as monoclinic or triclinic geometries. To obtain the background mechanisms of the crystal properties, the X-ray absorption fine structure spectroscopy technique was used to study the electronic properties of the samples. Prominent changes in the crystal structures due to 4f electrons’ contributions from the substituted Nd atoms as the main “role player” in the phase transitions were determined. The Nd atoms were observed as the key element guiding the entire phenomenon as a result of their large size and narrow 4f levels. Also, magnetic properties of the samples were tested at room temperature and without an applied magnetic field by X-ray magnetic circular dichroism study due to previous studies that reported the parent oxide CuFeO₂ to have magnetic ordering at T _N = 11 K (?262 °C). Except the sample for x = 1.0 (NdFeO₃), no magnetic ordering was observed at room temperature; i.e., all of the samples showed paramagnetic behaviors.