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At least 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

The Ce-Fe-Ti System: Phase Equilibria in the Fe-rich Corner at 1000 °C

The rare earth–iron–transition metal systems are of increasing interest in the search for novel permanent magnet phases. This work reports on the solidification behavior, phase equilibria and stability range of solid phases in the ternary Ce-Fe-Ti system, focusing on the iron-rich region (> 65 at.% Fe) of the isothermal section at 1000 °C. Further, two ternary phases Ce 1.03 Fe 12-x Ti x (x = 0.87–1.02) with ThMn 12 structure type and Ce 3.06 Fe 27.6 Ti 1.4 with Nd 3 Fe 29 structure type were observed. Magnetic measurements of Ce 1.03 Fe 12-x Ti x and Ce 3.06 Fe 27.6 Ti 1.4 revealed ferromagnetic ordering with Curie temperatures of 550 K and 327 K, respectively.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Insights into Ti doping for stabilizing the Na 2/3 Fe 1/3 Mn 2/3 O 2 cathode in sodium ion battery

Iron- and manganese-based layered metal oxides, as cathodes for sodium ion batteries, have received widespread attention because of the low cost and high specific capacity. However, the Jahn-teller effect of Mn 3+ ions and the resulted unstable structure usually lead to continuously capacity decay. Herein, Titanium (Ti) has been successfully doped into Na 2/3 Fe 1/3 Mn 2/3 O 2 to suppress the Jahn-Teller distortion and improve both cycling and rate performance of sodium ion batteries. In situ high-energy synchrotron X-ray diffraction study shows that Ti-doped compound (Na 2/3 Fe 1/3 Mn 0.57 Ti 0.1 O 2 ) can maintain the single P2 phase without any phase transition during the whole charging/discharging process. Further, various electrochemical characterizations are also applied to explore the better kinetics of sodium ions transfer in the Na 2/3 Fe 1/3 Mn 0.57 Ti 0.1 O 2 . This work provides a comprehensive insight into the Ti-doping effects on the performance from both structural and electrokinetic perspectives.

25 ENERGY STORAGE↗
DOE OSTI2020

Helium effects and bubbles formation in irradiated Ti 3 SiC 2

Ti 3 SiC 2 is a potential structural material for nuclear reactor applications. However, He irradiation effects in this material are not well understood, especially at high temperatures. Here, we compare the effects of He irradiation in Ti 3 SiC 2 at room temperature (RT) and at 750 °C. Irradiation at 750 °C was found to lead to extremely elongated He bubbles that are concentrated in the nano-laminate layers of Ti 3 SiC 2 , whereas the overall crystal structure of the material remained intact. In contrast, at RT, the layered structure was significantly damaged and highly disordered after irradiation. Our study reveals that at elevated temperatures, the unique structure of Ti 3 SiC 2 can accommodate large amounts of He atoms in the nano-laminate layer, without compromising the structural stability of the material. The structure and the mechanical tests results show that the irradiation induced swelling and hardening at 750 °C are much smaller than those at RT. Overall, these results indicate that Ti 3 SiC 2 has an excellent resistance to accumulation of radiation-induced He impurities and that it has a considerable tolerance to irradiation-induced degradation of mechanical properties at high temperatures.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Isotropic nanocrystalline Sm(Fe,Co) 11.3 Ti 0.7 magnets modified with B and Zr

Rare-earth-lean Sm(Fe,Co,Ti) 12 alloys with the ThMn 12 crystal structure and less than one Ti atom per formula unit have the potential of exceptionally powerful permanent magnets, but all prior attempts to develop high coercivity in bulk alloys, especially coercivity combined with crystallographic texture, have fallen short of the expectations. This study was aimed at improvement of the currently best Sm(Fe,Co,Ti) 12 magnets prepared through melt-spinning which are inherently isotropic. Modifications of the alloys with B and Zr, already demonstrated in earlier studies to be effective separately, have been implemented simultaneously. Here, a systematic study of Sm 1.1-x (Fe,Co) 11.3-y Ti 0.7 B y alloys melt-spun at a tangential speed of 50 m/s and annealed at 600–950 °C allowed for monitoring the continuous evolution of the two consecutive crystal structures, those of the TbCu 7 and ThMn 12 types. Zirconium was found to facilitate the formation of the 1:12 structure at the expense of the 1:7, whereas boron has the opposite effect, at certain concentrations completely suppressing the 1:12. When the two alloying elements are introduced simultaneously, they inhibit growth of the 1:12 crystallites at annealing temperatures higher than 800 °C, thus allowing for the development of a higher coercivity. Because of instrumental limitations, bulk magnets were prepared through a two-step process – compaction of the melt-spun ribbons at 650 °C and additional treatment at a higher temperature – and they were characterized by a reduced, 90–93%, density. Nevertheless, an isotropic Sm 0.9 Zr 0.2 (Fe,Co) 10.8 Ti 0.7 B 0.5 magnet exhibited fair values of the remanence (7.4 kG), maximum energy product (8.5 MGOe) and coercivity (5.4 kOe), as well as high Curie temperature of 525 °C and remarkably small temperature coefficient of the coercivity, -0.25%/°C.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Effect of alloying with Sc, Nb and Zr on reduction-diffusion synthesis of magnetically hard Sm(Fe,Co,Ti) 12 -based monocrystalline powders

Powders of Sm(Fe,Co) 11.2 Ti 0.8 alloys modified with Sc, Nb and Zr, as well as with additional Ti were prepared by reducing mechanically activated raw oxides with Ca metal in the furnace preheated to 990–1250 °C. Expansion of the crystal lattice upon introduction of Nb or additional Ti implies that atoms of these elements replace the smaller Fe atoms in the tetragonal ThMn 12 -type structure. On the other hand, contraction of the lattice upon introduction of Sc or Zr was smaller than what was expected for replacement of the Sm atoms, which suggests that the Sc and Zr atoms replace both the Sm and Fe atoms. Washing away the reduction byproducts expands the crystal lattice of the 1:12 particles and increases their coercivity. The lattice expansion associated with the washing is believed to be caused by interstitial H atoms; more research, however, is needed to establish the mechanism(s) of the washing effect on the coercivity. The earlier reported development of a high coercivity in zirconium-modified monocrystalline particles achieved by increasing the reduction annealing temperature to ≈1200 °C was similarly characteristic of the particles modified with Sc (the coercivity reaches 11.5 kOe) and Nb (8.1 kOe), but not for the particles prepared with additional Ti where the maximum coercivity of 8.3 kOe develops for a lower annealing temperature. Furthermore, it is concluded that Sc, Nb and Zr modify the high-temperature phase equilibria of the Sm(Fe,Co) 11.2 Ti 0.8 alloys allowing for an effective high-temperature processing, whereas the alloy coercivity increases with the synthesis temperature through a different, still unknown mechanism which may involve suppression of the defects specific to the 1:12 crystals.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Reconstructing parent microstructures in martensitic and pearlitic Ti-Cu

Evaluating the microstructural evolution of parent phases has long been a challenge in metals with a partial or complete solid state transformation. Most parent microstructure evolution has to be inferred from the product microstructure, with some information permanently lost. Parent microstructure reconstructions relying on orientation relationships and EBSD data are a useful tool to overcome this challenge, though much background knowledge is required to do so. Here, this work introduces a reconstruction process for a eutectoid composition Ti-Cu binary alloy to evaluate the high temperature β-Ti phase from martensitic and pearlitic product microstructures. Martensitic microstructures were accurately reconstructed, enabling elucidation of β-Ti grain size and texture, and the employed script included for scientific reference. Pearlitic microstructures did not reconstruct effectively with the current process. However, new insight into the interfacial crystallographic orientations of pearlitic Ti-Cu microstructures was gleaned via this analysis, and future investigations of interest are discussed accordingly. Ultimately, these findings demonstrate tools widely implemented on conventional titanium and ferrous alloys can also be applied to understand parent microstructures in Ti-Cu and other alloys of emerging interest. This is especially of use as new manufacturing processes for such materials require understanding how parent phase microstructures respond to new, novel material processing such as AM.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Development of coherent-precipitate-hardened high-entropy alloys with hierarchical NiAl/Ni 2 TiAl precipitates in CrMnFeCoNiAl x Ti y alloys

Coherent precipitates hardening is currently emerging strengthening mechanism of the various high entropy alloys (HEAs). Recently, CrMnFeCoNiAl x HEAs have been studied to show a phase transition from face-centered-cubic (FCC) to body-centered-cubic (BCC) and formation of coherent precipitates (B2-NiAl) within the BCC matrix. The coherent precipitates in the CrMnFeCoNiAl x alloys could contribute to increase the strength but lead to considerable reduction of the ductility. The present work systematically investigated a series of CrMnFeCoNiAl 0.5 Ti x alloys to further improve the strength and plasticity, as compared to the previously reported CrMnFeCoNiAl x HEAs. As a result, an increase of Ti addition leads to the phase transition from FCC to BCC and formation of lamellar structure and hierarchical precipitates reinforced by B2-NiAl and L2 1 -Ni 2 TiAl phases. Excellent mechanical properties were achieved from CrMnFeCoNiAl 0.5 Ti 0.1 and CrMnFeCoNiAl 0.5 Ti 0.2 alloys. Herein, the mechanical properties of the CrMnFeCoNiAl 0.5 Ti x alloys were discussed via theoretical strengthening mechanisms.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Interplay of strain and phase evolution of laser powder bed fusion Ti–6Al–4V

While additive manufacturing (AM) provides a method of producing geometrically complex and highly detailed structures, the generation of residual strain in AM processes like laser powder bed fusion (L-PBF) can negatively impact performance-enabling properties. In applications such as orthopedic implants, specific performance windows require optimized microstructures in order to obtain desirable properties from multi-phase alloys like Ti–6Al–4V. This research aims to quantify the microscale origins of strain in L-PBF manufactured Ti–6Al–4V by understanding how strain is distributed at the grain and sub-grain scale, the interplay between phase evolution and strain, and examining post-processing strain relief strategies to control these features. Model spinal cage implants were manufactured from Ti–6Al–4V powder via L-PBF and then subjected to strain relieving heat treatment cycles above and below the Ti–6Al–4V β transus as a function of time and cooling rate. Residual strain was then studied via high resolution electron backscatter diffraction (HR-EBSD), and 2D strain maps with sub-micron resolution were generated for each post-processing state. It was found that macroscale thermal strains decreased with heat treatment time, but additional contributions from phase stabilizing residual strains retained primarily in the α' grains as lattice distortive strain remained. Additionally, the retention of β phase significantly changed the strain and dislocation distribution while reducing overall residual strain. In conclusion, these results were validated and reinforced with 3D mesoscopic micromechanical modeling of strain behavior across simulated microstructures, confirming that the local lattice dilation of α’ martensite is a primary contributor of microscale strain generation and retention in L-PBF Ti–6Al–4V.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Synthesis of Ti 3 C 2 T z MXene from low-cost and environmentally friendly precursors

Herein we report an approach to synthesis Ti 3 AlC 2 MAX phase and Ti 3 C 2 T z MXene from low-cost precursors, viz. recycled carbon recovered from waste tire, recycled aluminum scrap, and titanium oxide. By adjusting the ratios of the initial materials, we determined that 3TiO 2 +6Al+1.9C resulted in the purest sample of Ti 3 AlC 2 when heated at 1,350 °C for 1 h. The MXene phase was synthesized by modified minimally intensive layer delamination and acid etching under N2 purging. The final Ti 3 C 2 T z films demonstrated conductivity of 5857 ± 680 S/cm and capacitance of 285 F/g (1,012 F/cm 3 ) at 20 mV/s scan rates, which are comparable with that produced from MAX phase of high-purity elemental precursors (viz. Ti, Al and C). Choosing readily available and inexpensive precursor materials such as these allows for a drastic reduction in production cost of the MXene, as well as reducing the environmental impact of the industry.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Solidification and crystallographic texture modeling of laser powder bed fusion Ti-6Al-4V using finite difference-monte carlo method

Laser powder bed fusion (LPBF) additive manufacturing makes near-net-shaped parts with reduced material cost and time, rising as a promising technology to fabricate Ti-6Al-4V, a widely used titanium alloy in aerospace and medical industries. However, LPBF Ti-6Al-4V parts produced with 67° rotation between layers, a scan strategy commonly used to reduce microstructure and property inhomogeneity, have varying grain morphologies and weak crystallographic textures that change depending on processing parameters. Here, this study predicts LPBF Ti-6Al-4V solidification at three energy levels using a finite difference-Monte Carlo method and validates the simulations with large-area electron backscatter diffraction (EBSD) scans. The developed model accurately shows that a <001> texture forms at low energy and a <111> texture occurs at higher energies parallel to the build direction but with a lower strength than the textures observed from EBSD. A validated and well-established method of combining spatial correlation and general spherical harmonics representation of texture is developed to calculate a difference score between simulations and experiments. The quantitative comparison enables effective fine-tuning of nucleation density (N 0 ) input, which shows a nonlinear relationship with increasing energy level. Future improvements in texture prediction code and a more comprehensive study of N 0 with different energy levels will further advance the optimization of LPBF Ti-6Al-4V components. These developments contribute a novel understanding of crystallographic texture formation in LPBF Ti-6Al-4V, the development of robust model validation and calibration pipeline methodologies, and provide a platform for mechanical property prediction and process parameter optimization.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2022

Titanium doped kagome superconductor CsV 3–x Ti x Sb 5 and two distinct phases

The vanadium-based kagome superconductor CsV 3 Sb 5 has attracted tremendous attention due to its unexcepted anomalous Hall effect (AHE), charge density waves (CDWs), nematicity, and a pseudogap pair density wave (PDW) coexisting with unconventional strong-coupling superconductivity. The origins of CDWs, unconventional superconductivity, and their correlation with different electronic states in this kagome system are of great significance, but so far, are still under debate. Chemical doping in the kagome layer provides one of the most direct ways to reveal the intrinsic physics, but remains unexplored. Here, we report, for the first time, the synthesis of Ti-substituted CsV 3 Sb 5 single crystals and its rich phase diagram mapping the evolution of intertwining electronic states. The Ti atoms directly substitute for V in the kagome layers. CsV 3–x Ti x Sb 5 shows two distinct superconductivity phases upon substitution. The Ti slightly-substituted phase displays an unconventional V-shaped superconductivity gap, coexisting with weakening CDW, PDW, AHE, and nematicity. The Ti highly-substituted phase has a U-shaped superconductivity gap concomitant with a short-range rotation symmetry breaking CDW, while long-range CDW, twofold symmetry of in-plane resistivity, AHE, and PDW are absent. Furthermore, we also demonstrate the chemical substitution of V atoms with other elements such as Cr and Nb, showing a different modulation on the superconductivity phases and CDWs. These findings open up a way to synthesise a new family of doped CsV 3 Sb 5 materials, and further represent a new platform for tuning the different correlated electronic states and superconducting pairing in kagome superconductors.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2020

Single-Layer Dititanium Oxide Ti 2 O MOene: Multifunctional Promises for Electride, Anode Materials, and Superconductor

Using the first-principles calculations, we report the existence of the single-layer (SL) dititanium oxide Ti 2 O (labeled as MOene) that constructs a novel family of MXene based on transition-metal oxides. This MOene material strongly contrasts the conventional ones consisting of transition-metal carbides and/or nitrides. SL Ti 2 O has high thermal and dynamical stabilities because of the strong Ti–O ionic bonding interactions. Moreover, this material is an intrinsic electride and exhibits extremely low diffusion barriers of ~12.0 and 6.3 meV for Li and Na diffusion, respectively. When applied as anode materials in lithium-ion batteries and sodium-ion batteries, it possesses a high energy storage capacity (960.23 mAhg –1 ), surpassing the traditional MXenes-based anodes. The superb electrochemical performance stems from the existing anionic electron on Ti 2 O surface. Astonishingly, SL Ti 2 O is also determined to be a superconductor with a superconducting transition temperature (T c ) of ~9.8 K, which originates from the soft-mode of the first acoustic phonon branch and enhanced electron–phonon coupling in the low-frequency region. Furthermore, this soft-mode behaves much softer upon applying a compressive strain of 2%, leading to a higher T c of 11.9 K. Furthermore, our finding broadens the family of MXenes and could facilitate more experimental efforts toward future nanodevices.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Etching-Chemistry-Driven Ruthenium Doping on Ti 3 C 2 T x MXene for Optimizing Electrochemical Performance

We demonstrate that the etching chemistry used during MXene synthesis from Ti 3 AlC 2 MAX phase significantly influences surface functionalization and structural vacancies, which in turn affect ruthenium (Ru) ion interactions. Using hydrofluoric acid (HF) and ammonium bifluoride (NH 4 HF 2 ) as etchants, we obtained MXene surfaces with distinct functional groups and Ti vacancies that impact Ru ion interactions and electrochemical performance. Both MXene variants (labeled MX(H) and MX(N), respectively) exhibited negative zeta potentials in their pristine state, but upon the addition of Ru the zeta potential for MX(H) reached 12.9 mV while that for MX(N) remained negative at −6.4 mV. This adsorption resulted in a 14.4-fold increase in the specific capacitance of MX(H)/Ru compared to pristine MX(H), whereas MX(N)/Ru exhibited only a 4.4-fold increase over its pristine counterpart. X-ray diffraction analysis identified the formation of ammonium titanium oxide fluoride, (NH 4 ) 3 TiOF 5 , on MX(N), which likely contributed to its reduced Ru adsorption. X-ray photoelectron spectroscopy suggested the presence of Ti vacancies in both MXene variants; however, their behavior toward Ru accommodation differed markedly, with MX(H) showing the most obvious shift in the Ti 2p peak in the XPS survey spectrum, while MX(N) showed the most obvious shift in the C 1s peak. Electron paramagnetic resonance spectroscopy further demonstrated a distinct alteration in the spectral signatures of MX(H) upon Ru addition, in contrast to the negligible changes in MX(N), indicating effective passivation of the Ti defect sites in MX(H) via vacancy-assisted Ru doping. Cyclic voltammetry showed that Ru-incorporated MX(H) nanocomposites exhibit more efficient redox-active sites, as reflected in their higher capacitance values. These findings highlight the pivotal role of MXene surface chemistry in controlling cation adsorption, providing valuable insights for the rational design of high-performance electrodes.

2D surface engineering↗
DOE OSTI2023

Improved thermonuclear rate of 42 Ti( p , γ ) 43 V and its astrophysical implication in the rp process

Context. Accurate 42 Ti(p,γ) 43 V reaction rates are crucial for understanding the nucleosynthesis path of the rapid capture process (rp process) that occurs in X-ray bursts. Aims. We aim to improve the thermonuclear rates of 42 Ti(p,γ) 43 V based on more complete resonance information and a more accurate direct component, together with the recently released nuclear masses data. We also explore the impact of the newly obtained rates on the rp process. Methods. We reevaluated the reaction rate of 42 Ti(p,γ) 43 V by the sum of the isolated resonance contribution instead of the Hauser-Feshbach statistical model. We used a Monte Carlo method to derive the associated uncertainties of new rates. The nucleosynthesis simulations were performed via the NuGrid post-processing code ppn. Results. The new rates differ from previous estimations due to the use of a series of updated resonance parameters and a direct S factor. Compared with the previous results from the Hauser-Feshbach statistical model, which assumes compound nucleus 43 V with a sufficiently high-level density in the energy region of astrophysical interest, large differences exist over the entire temperature region of rp-process interest, up to two orders of magnitude. We consistently calculated the photodisintegration rate using our new nuclear masses via the detailed balance principle, and found the discrepancies among the different reverse rates are much larger than those for the forward rate, up to ten orders of magnitude at the temperature of 10 8 K. Using a trajectory with a peak temperature of 1.95×10 9 K, we performed the rp-process nucleosynthesis simulations to investigate the impact of the new rates. Our calculations show that the adoption of the new forward and reverse rates result in abundance variations for Sc and Ca of 128% and 49%, respectively, compared to the variations for the statistical model rates. On the other hand, the overall abundance pattern is not significantly affected. The results of using new rates also confirm that the rp-process path does not bypass the isotope 43 V. Conclusions. Our study found that the Hauser-Feshbach statistical model is inappropriate to the reaction rate evaluation for 42 Ti(p,γ) 43 V. The adoption of the new rates confirms that the reaction path of 42 Ti(p,γ) 43 V(p,γ) 44 Cr(β + ) 44 V is a key branch of the rp process in X-ray bursts.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2020

Ti- and Fe-related charge transition levels in $β$ – Ga 2 O 3

Here, deep-level transient spectroscopy measurements on $β$ – Ga 2 O 3 crystals reveal the presence of three defect signatures labeled $E$ 2a , $E$ 2b , and $E$ 3 with activation energies at around 0.66 eV, 0.73 eV, and 0.95 eV below the conduction band edge. Using secondary ion mass spectrometry, a correlation between the defect concentration associated with $E$ 3 and the Ti concentration present in the samples was found. Particularly, it is found that $E$ 3 is the dominant Ti-related defect in $β$ – Ga 2 O 3 and is associated with a single Ti atom. This finding is further corroborated by hybrid functional calculations that predict Ti substituting on an octahedral Ga site, denoted as Ti GaII , to be a good candidate for $E$ 3 . Moreover, the deep level transient spectroscopy results show that the level previously labeled $E$ 2 and attributed to Fe substituting on a gallium site (FeGa) consists of two overlapping signatures labeled E2a and E2b. We tentatively assign $E$ 2a and $E$ 2b to Fe substituting for Ga on a tetrahedral or an octahedral site, respectively.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Isolated spin ladders in 𝐿⁢𝑛 2 ⁢Ti 9 ⁢Sb 11 (𝐿⁢𝑛 :La–Nd) metals

Here we present the discovery and characterization of a series of antimonides 𝐿⁢𝑛 2 ⁢Ti 9⁢ Sb 11 (Ln: La–Nd) that exhibit well-isolated, 𝑛 = 2 rare-earth spin ladders. We discuss the structure of these compounds, with a particular focus on the magnetic Ln spin ladders. Nd 2 ⁢Ti 9 ⁢Sb 11 and Ce 2 ⁢Ti 9 ⁢Sb 11 exhibit antiferromagnetic interactions and a well-defined doublet ground state, whereas Pr 2 ⁡Ti 9⁢ Sb 11 exhibits a weakly magnetic singlet ground state. Nd 2 ⁢Ti 9 ⁢Sb 11 is a poor metal with an electrical resistivity of 0.1m⁢Ω cm at 300 K and weak temperature dependence. The thermal conductivity along the ladder exhibits significant field dependence even at 40 K, considerably higher than the magnetic ordering temperature of 1.1 K. Compared to compounds with transition metal spin ladders, the rare-earth elements impart much lower energy scales, making these compounds highly tunable with external stimuli like magnetic fields. In conclusion, the diverse magnetism of the rare-earth ions and Ruderman-Kittel-Kasuya-Yosida interactions further contribute to the potential for a wide array of rich magnetic ground states, positioning these materials as a rare example of an inorganic square spin-ladder platform.

Crystal growth↗
DOE OSTI2023

Assessment of Directionally Solidified Eutectic Sm–Fe(Co)–Ti Alloys as Permanent Magnet Materials

Sm–Fe–Ti and Sm–Fe0.8Co0.2–Ti alloys were prepared via arc-melting and directionally solidified on a water-cooled copper hearth. The as-solidified alloys featured cells of the Sm(Fe,Co,Ti)12–Ti(Fe,Co) 2+δ –(α-Fe) lamellar eutectic. The lamellae of Sm(Fe,Co,Ti)12 phase with a crystal structure of the ThMn12 type were less than 0.2 μm thick, and had their [001] easy-magnetization directions oriented along the temperature gradient of the solidification. The eutectic microstructure led to an increased coercivity, especially in the Co-added alloys. Below 250 °C, this coercivity was found not to vary much with temperature with a temperature coefficient of -0.18 %/°C. However, the modest absolute values, reaching only 0.7 kOe, are insufficient for utilization of the directionally solidified alloys as anisotropic permanent magnets.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ti(FeGe)6 by Materials Project

TiFe6Ge6 crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. Ti is bonded to eight Ge atoms to form distorted edge-sharing TiGe8 hexagonal bipyramids. There are two shorter (2.67 Å) and six longer (2.87 Å) Ti–Ge bond lengths. Fe is bonded in a 12-coordinate geometry to six Ge atoms. There are a spread of Fe–Ge bond distances ranging from 2.45–2.58 Å. There are three inequivalent Ge sites. In the first Ge site, Ge is bonded in a 6-coordinate geometry to six equivalent Fe atoms. In the second Ge site, Ge is bonded in a 12-coordinate geometry to three equivalent Ti and six equivalent Fe atoms. In the third Ge site, Ge is bonded in a 8-coordinate geometry to one Ti, six equivalent Fe, and one Ge atom. The Ge–Ge bond length is 2.62 Å.

36 MATERIALS SCIENCE↗