Heavy RE Research Articles

Qualitative Identification of the Spin‐to‐Orbital Conversion Mechanism Modulated by Rare‐Earth Nd, Gd, and Ho Metals via Terahertz Emission Measurements

AbstractIt is crucial to study the materials that could effectively facilitate the inter‐conversion between charge, spin, and orbital degrees of freedom. In this work, the conversion among these three types of degrees of freedom in Pt/CoFeB/rare‐earth (RE, represents Nd, Gd, and Ho)/Ti multilayers is manipulated. Through terahertz (THz) emission measurements, it is found that the spin current induced by a femtosecond laser is converted into an orbital current via the spin‐orbit coupling of the RE layer. Notably, the light RE (Nd) and heavy RE (Gd and Ho) induce the orbital current with opposite polarization directions, ultimately leading to a weakening or enhancement of the THz emission intensity, respectively. Moreover, the fast Fourier transform reveals that Gd exerts the most significant influence on increasing the whole THz spectrum within the Pt/CoFeB/RE/Ti structure. The findings of RE‐modulated spin‐to‐orbital conversion provide valuable insights into the fundamental transport mechanism of the orbital current.

Dehydration Decreases Slow Wave Sleep After Heavy Resistance Exercise

Purpose: The purpose of this study was to examine the effects of hydration status on sleep and recovery measurement before and after high volume resistance exercise. It was hypothesized that dehydration decreases sleep and recovery measurements following exercise. Methods: Eight resistance-trained men (age, 21±2 years; weight, 82.0±12.6 kg; height, 177.3±6.9 cm) performed a series of bilateral leg press and knee extensions (RE, 5 sets of 10 repetitions at 80% of 1 repetition maximum). Participants completed one trial in a euhydrated state (EUH; urine specific gravity (USG) < 1.020) and the other in a dehydrated state (DEH: USG ≥ 1.020) which was separated by 2 weeks. For the DEH trial, participants were restricted from consuming fluids for 24 hours prior to the RE and were only permitted to drink 1.5 L of water post-exercise for the remainder of the day. For the EUH trial, participants were instructed to consume fluid for 24 hours prior to and 24 hours post RE to maintain euhydration. Sleep and recovery measurements were collected from a wearable sleep device that participants wore the night before (PRE) and after RE (POST). Repeated measures ANOVAs were used to identify the differences between EUH and DEH. Effect size (ES) was calculated with resulting effects identified as either small (0.2-0.49), medium (0.5-0.79), or large (>0.8) effects. Results: Slow wave sleep (SWS) (POST EUH, 1.4±0.5 hr; POST DEH, 1.0±0.5 hr; ES=0.8; p=0.028) and %SWS (POST EUH, 21.8±3.7 %; POST DEH, 14.3±6.4 %; ES=1.4; p=0.016) were greater in DEH compared to EUH at the night following RE. Also, SWS decreased at POST compared to PRE in DEH (PRE DEH, 1.4±0.3hr; ES=1.0; p=0.028), but not in EUH (PRE EUH, 1.2±0.6 hr; p=0.061). Sleep duration, sleep effciency, sleep disturbance, sleep deprivation, rapid eye movement sleep (REM), %REM, light sleep, resting heart rate, and heart rate variability were not different between EUH and DEH ( p>0.05). Conclusion: Dehydration decreases slow wave sleep following heavy RE, which potentially impairs recovery from exercise as SWS is important for physiological recovery. Therefore, it is critical to maintain euhydration to maximize recovery following an acute bout of RE. This study was funded by National Strength and Conditioning Association (NSCA). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Excellent cryogenic magnetocaloric properties in heavy rare-earth based HRENiGa2 (HRE = Dy, Ho, or Er) compounds

RENiX2 compounds, where RE = rare-earth element and X = p-block element, have been highly regarded for cryogenic magnetocaloric applications. Depending on the elements, they can crystallize in CeNiSi2-type, NdNiGa2-type, or MgCuAl2-type crystal structures, showing different types of magnetic ordering and thus affect their magnetic properties. Regarding the magnetocaloric effect, MgCuAl2-type aluminides show larger values than those of the CeNiSi2-type silicides and the NdNiGa2-type gallides due to the favored ferromagnetic ground state. However, RENiGa2 gallides can crystallize in either NdNiGa2- or MgCuAl2-type structures depending on the RE element. In this work, we select heavy RE (HRE) elements for exploring the microstructure, magnetic ordering and magnetocaloric performance of HRENiGa2 (HRE = Dy, Ho or Er) gallides. They all crystallize in the desired MgCuAl2-type crystal structure which undergoes a second-order transition from ferro- to para-magnetic state with increasing temperature. The maximum isothermal entropy change (∣∆Sisomax∣) values are 6.2, 10.4, and 11.4 J kg−1 K−1 (0–5 T) for DyNiGa2, HoNiGa2, and ErNiGa2, respectively, which are comparable to many recently reported cryogenic magnetocaloric materials. Particularly, the excellent magnetocaloric properties of HoNiGa2 and ErNiGa2 compounds, including their composite, fall in the temperature range that enables them for the in-demand hydrogen liquefaction systems.

Thermochemistry of sodium rare earth ternary fluorides, NaREF4

Sodium rare earth fluorides, NaREF4 (RE = rare earth), are used as luminescent materials for light emission and biomedical applications and are important compositions for extracting and separating RE elements. Solution calorimetric measurements of a series of β-structured NaREF4 (Na1.5RE1.5F6) phases with various RE elements determined their heats of formation. Though the lattice contracts from light to heavy RE elements, NaREF4 compounds show more exothermic enthalpies of formation from binary components with the decrease of RE3+ radii, contrary to behavior seen in most RE oxide ternary compounds. By constructing Born–Haber cycles, the different slopes of lines relating lattice energies to lattice parameters in binary and ternary fluorides appear to be the reason for this reverse trend, which can be associated with changes in the coordination number of RE cations. These trends and the metastability of sodium light RE fluorides not only reveal the key role of ionic radius in RE compound stability, but also are significant for the design and synthesis of new materials and motivate the more effective utilization of RE.

Thermochemistry of Sodium Rare Earth Ternary Fluorides, NaREF <sub>4</sub>

Sodium rare earth fluorides, NaREF4 (RE = rare earth), are used as luminescent materials for light emission and biomedical applications and are important compositions for extracting and separating RE elements. Solution calorimetric measurements of a series of β-structured NaREF4 (Na1.5RE1.5F6) phases with various RE elements determined their heats of formation. Though the lattice contracts from light to heavy RE elements, NaREF4 compounds show more exothermic enthalpies of formation from binary components with decrease of RE3+ radius, contrary to behavior seen in most RE oxide ternary compounds. By constructing Born–Haber cycles, the different slopes of lines relating lattice energies to lattice parameters in binary and ternary fluorides appear to be the reason for this reverse trend, which can be associated with changes in the coordination number of RE cations. These trends and the metastability of sodium light RE fluorides not only reveal the key role of ionic radius in RE compound stability, but also are significant for the design and synthesis of new materials and motivate the more effective utilization of RE.

Corrosion behaviour and cytocompatibility of selected binary magnesium-rare earth alloys

Abstract The corrosion behaviour of as-cast binary Mg–0.3Ce, Mg–1.44Nd, Mg–0.63Gd and Mg–0.41Dy (wt%) alloys was investigated in DMEM+10% FBS solution using electrochemical and weight loss tests. The results revealed that the alloys with heavy RE elements (Gd and Dy) exhibited the lowest corrosion rate compared to the alloys with light RE elements (Ce and Nd). The cytocompatibility of the Mg–RE alloys was assessed via live/dead straining after 3 and 7 days. The results show that Mg–0.63Gd alloy is a suitable candidate for biomedical applications.

Distribution Characteristics of Rare Earth Elements and Selenium in Hair of Centenarians Living in China Longevity Region.

In order to explore the characteristics of the rare earth elements (REEs) and selenium (Se) among the Chinese centenarians, the concentrations of REE and Se were detected in the hair of healthy centenarians living in typical Chinese longevity region, and the influences of physiological conditions and behavior on the concentrations of REE and Se were assessed. The average values of light RE (LRE) and heavy RE (HRE) are 31.87 and 11.12ng/g. Female centenarians had higher concentrations of lanthanum (La), praseodymium (Pr), gadolinium (Gd), terbium (Tb), erbium (Er), thulium (Tm), yttrium (Y), and Se but lower levels of cerium (Ce), neodymium (Nd), samarium (Sm), europium (Eu), dysprosium (Dy), holmium (Ho), ytterbium (Yb), and lutetium (Lu). Except for Ce, the higher the age, the lower the REE and Se content were. Smoking was positively associated with Dy, Er, and Yb levels, whereas drinking habits showed no significant effect on all the elements. Elderly individuals who ate smoked and pickled food and who consumed high amounts of salt had higher levels of REE and Se in their hair, and centenarians who consumed egg and milk had higher Se and REE in the hair than did the non-eaters. This comprehensive study on the REE and Se concentrations among the healthy centenarians can provide scientific support for shaping a healthy aging society.

Novel extractant (2,4-dimethylheptyl)(2,4,4′-trimethylpentyl)phosphinic acid (USTB-2) for rare earths extraction and separation from chloride media

Scientists have always been seeking more efficient extractants for rare earths extraction and separation, especially for heavy rare earths. In this paper, a novel extractant (2,4-dimethylheptyl)(2,4,4′-trimethylpentyl)phosphinic acid (USTB-2) was synthesized. The structures of the intermediate and USTB-2 were characterized by 31P NMR, 1H NMR, FT-IR and ESI-MS. Its pKa was 5.62. Its extraction ability was between Cyanex 272 and P507. Its extraction mechanism was cation exchange. Its extraction capacity was larger than that of Cyanex 272 and lower than that of P507. Its solubility in 3 mol/L HCl and deionized water was 11.2 mg/L and 19.0 mg/L, respectively. The Lu(III) loaded in USTB-2 solution can be easily stripped by HCl, HNO3 and H2SO4. It has good separation performance for heavy rare earths. Its average separation factor (β¯) for adjacent heavy REs from Gd to Lu was 2.18. For some heavy RE couples like Er/Ho, Yb/Tm and Lu/Yb (especially for Lu/Yb), USTB-2 possesses even better separation performance than Cyanex 272. Its extraction efficiency for nonferrous metal ions was in the order Al > Gd > Zn > Nd > La > Co > Cu. The separation factors of Al/Gd, Gd/Zn, Zn/Nd, La/Co by USTB-2 were 2.67, 5.39, 3.35 and 26.67, respectively.

Comparison of the acute perceptual and blood pressure response to heavy load and light load blood flow restriction resistance exercise in anterior cruciate ligament reconstruction patients and non-injured populations

ObjectivesTo compare the acute perceptual and blood pressure responses to: 1) light load blood flow restriction resistance exercise (BFR-RE) in non-injured individuals and anterior cruciate ligament reconstruction (ACLR) patients; and 2) light load BFR-RE and heavy load RE (HL-RE) in ACLR patients. DesignBetween-subjects, partially-randomised. MethodsThis study comprised 3 groups: non-injured BFR-RE (NI-BFR); ACLR patients BFR-RE (ACLR-BFR); ACLR patients HL-RE (ACLR-HL). NI-BFR and ACLR-BFR performed 4 sets (30, 15, 15, 15 reps, total = 75 reps, 30s inter-set rest) of unilateral leg press exercise at 30% 1RM with continuous BFR at 80% limb occlusive pressure. ACLR-HL performed 3 × 10 reps (Total = 30 reps, 30s inter-set rest) of unilateral leg press exercise at 70% 1RM. Perceived exertion (RPE), muscle pain, knee pain and pre- and 5-min post-exercise blood pressure were measured. ResultsRPE was higher in ACLR-BFR compared to NI-BFR (p < 0.05). Muscle pain was higher in NI-BFR and ACLR-BFR compared to ACLR-HL (p < 0.05). Knee pain was lower in ACLR-BFR compared to ACLR-HL (p < 0.01). There were no differences in blood pressure. ConclusionThese responses to BFR exercise may not limit application and favourably influence knee pain throughout ACLR rehabilitation training programmes. These findings can help inform practitioners' decisions to utilise this tool.

Extractant (2-ethylhexyl)(2,4,4′-trimethylpentyl)phosphinic acid (USTB-1): Synthesis and its extraction and separation behaviors for rare earths from chloride media

Abstract By combining the structures of P227 and Cyanex 272, a nonsymmetric dialkylphosphinic acid USTB-1 was synthesized. Its structure was confirmed by 31P NMR, 1H NMR, MS and IR. Its pKa and purity were determined through potentiometric titration method. Its extraction and separation performance for RE(III) were studied. The purity of USTB-1 was 97.6%. Its pKa was 5.73, which was very close to that of P227 and Cyanex 272. Its solubility in deionized water was 34.7 mg/L. Its extraction ability was equal to that of P227 and Cyanex 272. It can reach extraction equilibrium as fast as Cyanex 272. Its complex with Lu(III) has larger solubility in n-octane than that of Cyanex 272, which indicated that USTB-1 has higher extraction capacity than Cyanex 272. The Lu(III) loaded in USTB-1 solution can be stripped by HCl as easily as the Lu(III) loaded in P227 and Cyanex 272 solutions. USTB-1 has good separation performance for RE(III), especially for heavy RE(III). Its average separation factor of adjacent heavy RE(III) from Ho to Lu was 2.21, superior to Cyanex 272 ( β N + 1 / N ‾ from Ho to Lu: 2.08).

Extractant (2,3-dimethylbutyl)(2,4,4′-trimethylpentyl)phosphinic acid (INET-3) impregnated onto XAD-16 and its extraction and separation performance for heavy rare earths from chloride media

(2,3-Dimethylbutyl)(2,4,4′-trimethylpentyl)phosphinic acid (INET-3) was impregnated onto dry macroporous resins XAD-16 and pretreated XAD-16 with ethyl alcohol and HCl (Pre-XAD-16) to prepare the solvent impregnated resins SIRs-INET-3/XAD-16 and SIRs-INET-3/Pre-XAD-16. The molecular weight distribution of the low molecular weight (LMW) polymers washed off by ethyl alcohol during XAD-16 pretreatment was determined by gel permeation chromatography (GPC). The macroporous resins (XAD-16 & Pre-XAD-16), the corresponding solvent impregnated resins (SIRs-INET-3/XAD-16 & SIRs-INET-3/Pre-XAD-16) and the PVA coated SIRs-INET-3/Pre-XAD-16 with boric acid as cross-linking agent were characterized by FT-IR, SEM-EDS and TGA. The effects of XAD-16 pretreatment and PVA coating technology on RE(III) adsorption equilibrium time, INET-3 losses during extraction and adsorption capacity were investigated. The adsorption kinetics, selectivity and stripping behaviors of SIRs-INET-3/XAD-16 were further studied. The washed off LMW polymers had the Mn of 36,656, Mw of 40,310 and polydispersity coefficient of 1.10. The SIRs-INET-3/XAD-16 had shorter equilibrium time, less INET-3 loss and more Tm(III) adsorption capacity than the SIRs-INET-3/Pre-XAD-16. The PVA coated SIRs-INET-3/Pre-XAD-16 had less INET-3 loss and more Tm(III) adsorption capacity but longer equilibrium time than the uncoated SIRs-INET-3/Pre-XAD-16. The adsorption of RE(III) on the SIRs-INET-3/XAD-16 followed the pseudo-second-order kinetic model. The Tm(III) accumulative adsorption amounts onto SIRs-INET-3/XAD-16 after eight extraction stages was 23.6 mg/g. The separation factors of adjacent heavy RE(III) βEr/Ho, βTm/Er, βYb/Tm and βLu/Yb values were 1.76, 2.59, 2.56 and 1.19, respectively. The adsorbed Lu(III) onto the SIRs-INET-3/XAD-16 can be stripped completely by 1.0 mol/L H2SO4.

Critical Systematic Evaluation and Thermodynamic Optimization of the Fe-RE System: RE = Gd, Tb, Dy, Ho, Er, Tm, Lu, and Y

As the second part of the thermodynamic study of binary Fe-RE system, critical evaluations and optimizations of all available phase diagrams and thermodynamic data for the Fe-heavy RE (heavy RE = Gd, Tb, Dy, Ho, Er, Tm, Lu, and Y) systems were conducted to obtain reliable thermodynamic functions of all the phases in the systems. In the thermodynamic modeling of the heavy RE systems, systematic variations in the phase diagrams and thermodynamic properties such as the enthalpy of mixing in the liquid state and enthalpy of formation of solid compounds with the atomic number of lanthanide series were observed. These systematic trends were incorporated in the optimization of the Fe-heavy RE system to resolve inconsistencies between available experimental data and to estimate unknown thermodynamic properties. The systematic trends in thermodynamic properties of solid and liquid phases and phase diagram of the entire Fe-RE systems were summarized.

Biaxial magnetic alignment in twinned REBa2Cu3Oy superconductors

Biaxial magnetic alignment of REBa2Cu3Oy (RE123, RE = Y, Nd, Sm, Dy, and Er) superconductor powders containing twin microstructures was demonstrated. Appropriate choice of RE effectively improved the degrees of in-plane and c-axis orientation in RE123 powder samples aligned under modulated rotating magnetic fields at room temperature. From the relationship between the magnetic field strength and the degrees of orientation, it is concluded that heavy RE ions induced the improvement of the in-plane magnetic anisotropies in RE123 grains with twin microstructures.

Magnetocaloric effect of Fe–RE–B–Nb (RE = Tb, Ho or Tm) bulk metallic glasses with high glass-forming ability

The magnetocaloric effect of (Fe0.71RE0.05B0.24)96Nb4 (RE=Tb, Ho and Tm) bulk metallic glasses (BMGs) of diameters up to 6.5mm were attained by 4.8at.% RE alloying. The Curie temperature (TC) of Tm doped alloy, being the highest among these alloys, deviates from typical relationship between TC and de Gennes factor. Its unique electronic structure has been suggested to attribute to the observed trend. Furthermore, Tm doped alloy presents the largest peak magnetic entropy change (|ΔSMpk|) of 1.21Jkg−1K−1 for an applied field of 1.5T, which compares favorably with those of other Nanoperm-type alloys. The phenomenological universal curve for ΔSM demonstrates that alloys exhibit similar critical exponents at TC. This family of heavy RE doped Fe-based BMGs is potential candidate used as bulk magnetic refrigerants with the final required shapes.

Effect of Ce-Mg-Si and Y-Mg-Si nodulizers on the microstructures and mechanical properties of heavy section ductile iron

Effect of Ce-Mg-Si (light RE) and Y-Mg-Si (heavy RE) nodulizers on the microstructures and mechanical properties of heavy section ductile iron was investigated to develop the material of spent-nuclear-fuel containers. Two as-casts were treated by the same quality percentage of light RE and heavy RE, respectively. Four positions were chosen to stand for different solidification cooling rates of specimens. The tensile strength, elongation and impact toughness of specimens treated by heavy RE were all higher than those of the specimens treated by light RE. With the decrease of cooling rate, the mechanical properties of two specimens decreased, and the fracture morphology changed from ductile fracture to brittle fracture. The improving effect of mechanical properties between heavy RE and light RE was obvious due to the better anti-degradation property of heavy RE. While the solidification process lasted for more than 250 min, the improving effect was not obvious due to serious spheroidalization decaying.

Hydrogen absorption in RE2T2In compounds

• Hydrogenation on selected RE 2 T 2 X was performed. • Nd 2 Ni 2 In is unique among “221” compounds, exhibiting a very high H absorption. • The behavior found in RE 2 Ni 2 In changes when replacing Ni for Pd. • The amorphization of La 2 Pd 2 In allows to go up to 4.6 H/f.u. • RE 2 Pd 2 In with heavy RE can absorb 2 H/f.u. without structure distortion. RE 2 T 2 In compounds (RE = rare earth, T is a late transition metal) were found, depending on the composition, absorbing different amounts of H. Several types of reaction of crystal structure have been found. Mere volume expansion, analogous to U 2 T 2 X compounds, was found e.g. in Tb 2 Pd 2 In, allowing to accommodate up to 2 H atoms/f.u. (one formula unit comprises 2 RE atoms). More dramatic structure modifications are required, to keep the H–H spacing higher than 2.1 Å, for higher H absorption. One type of reaction is amorphization, observed in La 2 Pd 2 In. Other type was observed in Nd 2 Ni 2 In, undergoing an orthorhombic distortion and forming four different H sites. The volume expansion exceeds 23%.

Microstructure of Al 3Sc with ternary rare-earth additions

The microstructure of ternary L1 2-Al 3(Sc 1− y RE y ) intermetallics, where RE is one of the rare-earth elements selected from five light (La, Ce, Nd, Sm or Eu) or two heavy lanthanoids (Yb or Lu), was investigated as a function of RE concentration for 0.02 ≤ y ≤ 0.75. Alloys with light RE show two phases: L1 2-Al 3(Sc,RE) and D0 19-Al 3(RE,Sc) (or C11 b-Al 4(Eu,Sc)). Alloys with heavy RE exhibit a single L1 2-Al 3(Sc,RE) phase. The maximum RE solubility in the L1 2 phase is very low (<0.4 at.%) for La, Ce, Nd and Eu, low (3.2 at.%) for Sm and complete solid-solution for Yb and Lu. Both lattice parameter and hardness of the L1 2-Al 3(Sc,RE) phases increase linearly with Sm, Yb or Lu concentration, and the magnitude of both effects correlates with the atomic size mismatch between Sc and RE.

Influence of Structure and Ionic Radius on Solubility Limit in the Mg–Re Systems

The relationship between structure, ionic radius and electronegativity and solubility of the various rare-earth elements in Mg was studied. It is found that light RE(La-Sm, Eu, Yb) have more complicated phase relation with Mg but the heavy RE(Gd-Lu, Sc) have the similar crystal structure with magnesium. Also it is found that the less electronegativity difference between Mg and RE is, the more solubility limit of RE in Mg is. The fact of the RE solubility decreased in magnesium with lowering temperature suggests that there is a possibility of Mg supersaturated solid solution formation and it will decomposition during aging. According to the rule, an megnesium alloy with higher strength feature was developed. Their mechanical properties are UTS 347MPa, YTS 290MPa and elongation 12.5% at room temperature.

Impregnation synthesis of a novel macroporous silica-based TODGA polymeric composite and its application in the adsorption of rare earths in nitric acid solution containing diethylenetriaminepentaacetic acid

A macroporous silica-based N, N, N′, N′-tetraoctyl-3-oxapentane-1,5-diamide (TODGA) polymeric composite (TODGA/SiO 2-P) was synthesized. It was done through impregnation and immobilization of TODGA molecule into the pores of the SiO 2-P particles utilizing a vacuum sucking technique. The macroporous SiO 2-P particles were the silica-based organic/inorganic composite synthesized by immobilizing styrene–divinylbenzene copolymer inside SiO 2 through the complicated polymerization reaction. The adsorption of rare earth (RE(III)) elements onto TODGA/SiO 2-P was investigated in HNO 3 solution containing diethylenetriaminepentaacetic acid (DTPA), an acidic multi-dentate chelating agent. It was found that in the presence of 0.05 M DTPA, NO 3 - and H + had significant effect on the TODGA/SiO 2-P adsorption due to the competition reactions of RE(III) with different species, H 4DTPA − and H 2DTPA 3−. With an increase in the concentration of NO 3 - from 0.115 M to 3.015 M, the adsorption of RE(III) onto TODGA/SiO 2-P increased noticeably. On the other hand, RE(III) showed strong adsorption at 0.1 M H +, weak adsorption at around pH 2, and no adsorption in excess of pH 2.3. In a 0.1 M H +–0.115 M NO 3 - –0.05 M DTPA solution, a change of the distribution coefficient of RE(III) onto TODGA/SiO 2-P with an increase in atomic number of RE(III) from La(III) to Lu(III) was investigated. The silica-based TODGA/SiO 2-P polymeric composite showed strong adsorption for heavy RE(III) over the light one. In a 0.01 M H +–1.0 M NO 3 - –0.05 M DTPA solution, the effect of the ratio of solid phase to liquid one on the relationship of the distribution coefficient of RE(III) with the change in atomic number of RE(III) was also studied. Based on the complicated disassociation equilibrium of DTPA, the influence of the concentrations of NO 3 - and H + on the adsorption of TODGA/SiO 2-P for RE(III) was demonstrated. This makes the partitioning of RE(III) and MA(III) together from high level liquid waste (HLLW) by the polymeric composite TODGA/SiO 2-P promising.

Synthesis of two novel macroporous silica-based impregnated polymeric composites and their application in highly active liquid waste partitioning by extraction chromatography

Two kinds of novel macroporous silica-based chelating polymeric adsorption materials, TODGA/SiO2-P and CMPO/SiO2-P, were synthesized by impregnating and immobilizing two chelating agents, N,N,N',N'-tetraoctyl-3-oxapentane-1,5-diamide (TODGA) and octyl(phenyl)-N,N-diisobutylcarbamoylmethylphoshine oxide (CMPO), into the pores of SiO2-P particles. To separate minor actinides (MA(III)) such as Am(III) and Cm(III), the adsorption and elution of 13 typically simulated fission products from a 3 M HNO3 were performed. It was found that in the first column packed with TODGA/SiO2-P, all of the simulated elements were separated effectively into four groups: (1) Cs(I), Mo(VI), and the most portion of Ru(III) (non-adsorption group), (2) Sr(II), small portion of Gd(III) and all of light REs(III) (MA-lRE-Sr group), (3) most of Gd(III) and all heavy RE(III) (hRE group), and (4) Zr(IV), Pd(II), and a little of Ru(III) (Zr-Pd group) by eluting with 3.0 M HNO3, 1.0M HNO3, distilled water, and 0.5 M H2C2O4, respectively, at 298 K. MA(III) was predicted to flow into the second group along with Nd(III) because of their close adsorption-elution onto TODGA/SiO2-P. In the second column packed with CMPO/SiO2-P, MA-lRE-Sr group was separated into (1) Sr(II), (2) middle RE(III) such as Gd(III), Eu(III), Sm(III), and quite small portion of Nd(III) (MA-mRE), and (3) light RE(III) such as La(III), Ce(III), and most of Nd(III) by eluting with 3.0 M HNO3 and 0.05 M DTPA-pH 2.0, respectively, at 323 K. MA(III) was believed to flow into MA-mRE group along with Gd(III) due to their similar adsorption properties towards CMPO/SiO2-P. Based on positions of MA(III) appeared in light and heavy RE(III), an improved MAREC process for MA(III) partitioning from HLW was proposed.