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At least 1,603 records · Page 89
All sourcesNASA NTRSDOE OSTI
DOE OSTI2015

Magnetic enhancement and coding in mechanosynthesized Ni{sub 0.3}Zn{sub 0.7}Fe{sub 2}O{sub 4} nanoparticles

The nanosized Ni{sub 0.3}Zn{sub 0.7}Fe{sub 2}O{sub 4} (∼ 15 nm) has been synthesized by high energy ball milling of the bulk powder sample. The sample has been characterized by powder x-ray diffraction, field emission and transmission electron microscopic and dc magnetic measurement techniques. The dc magnetic measurement on the sample indicates that the sample exhibit enhancement of magnetization compared to its counterparts synthesized by chemical methods. Moreover, the system stores the memory of either decrease or increase of magnetic field enabling a magnetic coding of “0” and “1” which can be profitably used in magnetic storage and sensing devices.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2016

In situ neutron scattering study of nanoscale phase evolution in PbTe-PbS thermoelectric material

Introducing nanostructural second phases has been proved to be an effective approach to reduce the lattice thermal conductivity and thus enhance the figure of merit for many thermoelectric materials. Furthermore studies of the formation and evolution of these second phases are central to understanding temperature dependent material behavior, improving thermal stabilities, as well as designing new materials. We examined powder samples of PbTe-PbS thermoelectric material using in situ neutron diffraction and small angle neutron scattering (SANS) techniques from room temperature to elevated temperature up to 663 K, to explore quantitative information on the structure, weight fraction, and size of the second phase. Neutron diffraction data showed the as-milled powder was primarily solid solution before heat treatment. During heating, PbS second phase precipitated out of the PbTe matrix around 480 K, while re-dissolution started around 570 K. The second phase remained separated from the matrix upon cooling. Furthermore, SANS data indicated there are two populations of nanostructures. The size of the smaller nanostructure increased from initially 5 nm to approximately 25 nm after annealing at 650 K, while the size of the larger nanostructure remained unchanged. Our study demonstrated that in situ neutron techniques are effective means to obtain quantitative information to study temperature dependent nanostructural behavior of thermoelectrics and likely other high-temperature materials.

36 MATERIALS SCIENCE↗
DOE OSTI2024

The Role of Alkalis in Orchestrating Uranyl-Peroxide Reactivity Leading to Direct Air Capture of Carbon Dioxide

Spectator ions have known and emerging roles in aqueous metal-cation chemistry, respectively directing solubility, speciation, and reactivity. Here, in this work, we isolate and structurally characterize the last two metastable members of the alkali uranyl triperoxide series, the Rb + and Cs + salts (Cs-U 1 and Rb-U 1 ). We document their rapid solution polymerization via small-angle X-ray scattering, which is compared to the more stable Li + , Na + and K + analogues. To understand the role of the alkalis, we also quantify alkali-hydroxide promoted peroxide deprotonation and decomposition, which generally exhibits increasing reactivity with increasing alkali size. Cs-U 1 , the most unstable of the uranyl triperoxide monomers, undergoes ambient direct air capture of CO 2 in the solid-state, converting to Cs 4 [U VI O 2 (CO 3 ) 3 ], evidenced by single-crystal X-ray diffraction, transmission electron microscopy, and Raman spectroscopy. We have attempted to benchmark the evolution of Cs-U 1 to uranyl tricarbonate, which involves a transient, unstable hygroscopic solid that contains predominantly pentavalent uranium, quantified by X-ray photoelectron spectroscopy. Powder X-ray diffraction suggests this intermediate state contains a hydrous derivative of CsU V O 3 , where the parent phase has been computationally predicted, but not yet synthesized.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2016

Morphological Comparison of U3O8 Ore Concentrates from Canada Key Lake and Namibia Sources

Uranium ore concentrates from two different sources were examined using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The ore powders are referred to as Namibia (id. no. 90036, LIMS id. no. 18775) and Canada Key Lake (id. no. 90019, LIMS id. no. 18774). Earlier work identified the ores as the U₃O₈ phase of uranium oxide using x-ray diffraction. Both sets of powders were in the form of dark brown to black powder fines. However, the Canada Key Lake concentrates contained larger chunks of material on the millimeter scale that were easily visible to the unaided eye. The powders were mounted for SEM examination by hand dispersing a small amount onto conductive sticky tape. Two types of applicators were used and compared: a fine-tipped spatula and a foam-tipped applicator. The sticky tape was on a standard SEM “tee” mount, which was tapped to remove loose contamination before being inserted into the SEM.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2018

Influence of Iron Content on Microstructure and Magnetic Properties of Sr{sub 0.3}La{sub 0.4}Ca{sub 0.3}n(Fe{sub 2}O{sub 3})Co{sub 0.4}

In this work, the hexagonal ferrite Sr{sub 0.3}La{sub 0.4}Ca{sub 0.3}n (Fe{sub 2}O{sub 3})Co{sub 0.4}, where n ranging from 5.5 to 6.0 with a step of 0.1, and magnetic powders and magnets were synthesized by solid-states reaction. The microstructure of the magnetic powders was investigated by X-ray diffraction (XRD). And then we can found that a single magnetoplumbite phase is obtained for magnetic powders as a result when 5.6 ≤ n ≤ 5.8. When the iron content in the magnetic powders increased continuously, the diffraction peaks of α-Fe{sub 2}O{sub 3} were observed. Scanning electron microcopy (SEM) was used to explore the micrographs of the magnets and the hexagonal-shaped crystals were found obviously. The magnetic properties of the M-type hexagonal ferrites Sr{sub 0.3}La{sub 0.4}Ca{sub 0.3}n(Fe{sub 2}O{sub 3})Co{sub 0.4} were studied by using vibrating sample magnetometry. The saturation magnetization (M{sub s}) first increased and then began to decrease with the n increasing. While the coercivity first decreased with the n from 5.5 to 5.9 and then increased when n ≥5.9. The coercivity (H{sub c}) of the hexagonal ferrite Sr{sub 0.3}La{sub 0.4}Ca{sub 0.3}n(Fe{sub 2}O{sub 3})Co{sub 0.4} reaches the maximum value (H{sub c} = 1130 Oe) when the iron content (n = 5.5).

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2025

Suppressing Ordering in Equiatomic Fe-Co via Laser Powder Bed Fusion

Neutron and electron diffraction was employed to evaluate the effectiveness of thermal management strategies in suppressing the formation of the equilibrium-ordered B2 (CsCl) phase in equiatomic binary Fe-Co specimens fabricated by laser powder bed fusion additive manufacturing. Specimens with a tensile dogbone geometry were fabricated using various combinations of process parameters (laser power and raster speed) and thermal management strategies (no support struts, struts only in the top gauge section, and struts throughout the gauge section). Diffraction results demonstrate that the rapid solidification during PBF-L effectively minimized B2 formation, with laser power and effective scan velocity having no significant impact on the degree of ordering. Furthermore, the inclusion of support struts in the top grip region had no perceivable impact on ordering, whereas specimens with support struts in the gauge region exhibited no detectable ordering. Results are discussed in the context of thermal finite element analysis predictions.

Laser Material Processing↗
DOE OSTI2019

Enhanced Magneto-optical and Antibacterial Studies of Bi{sub 1−x}Mg{sub x}FeO{sub 3} (0.0 ≤ x ≤ 0.15)) Nanoparticles

Mg-doped BiFeO{sub 3} (Bi{sub 1−x}Mg{sub x}FeO{sub 3} (0.00 ≤ x ≤ 0.15)) nanoparticles (NPs) have been successfully prepared by simple solution combustion method using urea as fuel. The obtained product was sintered at 550 °C for 2 h to get pure-phase formation. The as-prepared samples were characterized by powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscope (TEM), ultraviolet–visible (UV-Vis) absorption, photoluminescence (PL) spectra, and vibrating sample magnetometer (VSM) analysis. Powder XRD study revealed that all products exhibit rhombohedral structure with pure-phase formation. The average crystallite size of the samples decreased from 56.25 to 46.15 nm with increasing the concentration of Mg (x = 0.00, 0.05, 0.10, and 0.15). Surface morphology of the samples were analyzed by FE-SEM and TEM micrograph techniques, and the grain distribution was not quite homogeneous and observed agglomeration of the particles, which is mainly due to the magnetic interaction among them. EDX analysis confirmed the presence of Bi, Fe, O, and Mg elements without any form of impurity peak in all products. PL spectra shows a high intense peak at 464 nm, which is attributed to blue emission. The saturation magnetization is enhanced with increasing Mg doping level at RT. Antibacterial activity of Bi{sub 1−x}Mg{sub x}FeO{sub 3} NPs was found to be enhanced with increase in Mg doping concentration as it causes a reduction in the grain size of the samples.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2015

Hybrid Inorganic-Organic Materials with an Optoelectronically Active Aromatic Cation: (C 7 H 7 ) 2 SnI 6 and C 7 H 7 PbI 3

Inorganic materials with organic constituents—hybrid materials—have shown incredible promise as chemically tunable functional materials with interesting optical and electronic properties. Here, the preparation and structure are reported of two hybrid materials containing the optoelectronically active tropylium ion within tin- and lead-iodide inorganic frameworks with distinct topologies. The crystal structures of tropylium tin iodide, (C 7 H 7 ) 2 SnI 6 , and tropylium lead iodide, C 7 H 7 PbI 3 , were solved using high-resolution synchrotron powder X-ray diffraction informed by X-ray pair distribution function data and high-resolution time-of-flight neutron diffraction. Tropylium tin iodide contains isolated tin(IV)-iodide octahedra and crystallizes as a deep black solid, while tropylium lead iodide presents one-dimensional chains of face-sharing lead(II)-iodide octahedra and crystallizes as a bright red-orange powder. Experimental diffuse reflectance spectra are in good agreement with density functional calculations of the electronic structure. Calculations of the band decomposed charge densities suggest that the deep black color of tropylium tin iodide is attributed to iodide ligand to tin metal charge transfer, while the bright red-orange color of tropylium lead iodide arises from charge transfer between iodine and tropylium states. Understanding the origins of the observed optoelectronic properties of these two compounds, with respect to their distinct topologies and organic–inorganic interactions, provides insight into the design of tropylium-containing compounds for potential optical and electronic applications.

Maughan, Annalise E.↗
DOE OSTI2014

Synthesis and characterization of O3-Na{sub 3}LiFeSbO{sub 6}: A new honeycomb ordered layered oxide

Highlights: • A new honeycomb ordered layered oxide Na{sub 3}LiFeSbO{sub 6} was synthesized. • This compound crystallizes in the C2/c space group. • Disorder in the honeycomb arrangement of Li and Fe is present. - Abstract: A new compound Na{sub 3}LiFeSbO{sub 6} has been synthesized by conventional solid state methods and investigated using X-ray diffraction, DC magnetic susceptibility, {sup 57}Fe Mössbauer spectroscopy and optical measurements. This compound crystallizes in a monoclinic unit cell and is related to a family of honeycomb ordered layered oxide materials where Na{sup +} fills octahedral interlayer sites between Li{sub 1/3}Fe{sub 1/3}Sb{sub 1/3}O{sub 2} slabs of edge sharing octahedra. Each SbO{sub 6} octahedron is surrounded by LiO{sub 6} and FeO{sub 6} octahedra creating a honeycomb arrangement within the slabs. Powder X-ray diffraction indicates the presence of stacking faults. This compound exhibits Curie–Weiss behavior at high temperatures and the effective magnetic moment verifies the presence of high spin Fe{sup 3+}. The {sup 57}Fe Mössbauer spectroscopy confirms Fe{sup 3+} in an octahedral position and indicates disorder in the arrangement of LiO{sub 6} and FeO{sub 6} octahedra in the Li{sub 1/3}Fe{sub 1/3}Sb{sub 1/3}O{sub 2} slabs.

36 MATERIALS SCIENCE↗
DOE OSTI2014

Solid state {sup 31}P MAS NMR spectroscopy and conductivity measurements on NbOPO{sub 4} and H{sub 3}PO{sub 4} composite materials

A systematic study of composite powders of niobium oxide phosphate (NbOPO{sub 4}) and phosphoric acid (H{sub 3}PO{sub 4}) has been performed in order to characterize the material's ability to perform as an electrolyte material in medium temperature fuel cells and electrolyzers. Powders of H{sub 3}PO{sub 4} contents between 13.1 and 74.2 M% were produced and characterized with powder X-ray diffraction, {sup 31}P MAS NMR and impedance spectroscopy. NMR revealed that a significant degree of dehydration and vaporization of H{sub 3}PO{sub 4} takes place above 200 °C, and increases with temperature. At 500 °C the NbOPO{sub 4} and H{sub 3}PO{sub 4} has reacted to form niobium pyrophosphate (Nb{sub 2}P{sub 4}O{sub 15}). Impedance spectroscopy showed an increase in conductivity with increasing acid concentration, whereas the conductivity decreased slightly with increasing temperature. The highest conductivity measured was 2.5·10{sup −3} S/cm for a sample containing 74.2 M% of H{sub 3}PO{sub 4}. Lastly, it was shown that NbOPO{sub 4} has no significant conductivity of its own. - Graphical abstract: Conductivity of NbOPO{sub 4}/H{sub 3}PO{sub 4} composites as a function of equivalent P{sub 2}O{sub 5} content. The conductivity is insignificant for pure NbOPO{sub 4}. - Highlights: • Composites have been made from NbOPO{sub 4} and H{sub 3}PO{sub 4}. • The composites composition has been investigated with solid state NMR. • The composites have shown clear signs of acid dehydration upon heating. • The conductivity of the composites increases for increasing acid content. • NbOPO{sub 4} has no significant conductivity of its own.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2014

Studies on L-citrulline doped potassium dihydrogen phosphate- A non linear crystal with significant nonlinear properties

Potassium Dihydrogen Phosphate (KDP) single crystal is considered as one of the best representative of nonlinear optical crystals. Recently, amino acids having excellent nonlinear optical characteristics are being investigated as prospective dopants to improve the non linear optical characteristics of KDP. The present work is an attempt in this direction and L citrulline, one of the non essential amino acids showing good non linear optical characteristics is used as the dopant for KDP. Good quality crystals of L-citrulline doped KDP crystals were grown by slow evaporation technique. From the powder X-ray diffraction studies of doped KDP crystal, the structure of the doped crystals was determined by direct method and refined by Pawley method employing Topaz version program using the single crystal X-ray data for pure KDP. The lattice parameters for L citrulline doped KDP are a=7.467A{sup 0}, b=7.467 A{sup 0}, c=6.977 A{sup 0}. The crystal falls into the tetragonal crystal system with space group I42 d. The presence of carbon and oxygen, which are primary components of amino acids, in the EDAX spectrum confirms the effectiveness of doping. The absorption spectra of the doped samples show that the crystals are transparent in the entire visible region. The second harmonic generation efficiency of the doped samples was determined by Kurtz powder technique using the Q-switched Nd:YAG laser beam and is found to be 2.2 times that of KDP. The nonlinear optical properties can be well studied by the open aperture Z scan technique. The open aperture curve exhibits a normalized transmittance valley. The nonlinear absorption coefficient β is obtained by theoretical fitting for two photon absorption. It is inferred that doping KDP with L citrulline has enhanced the nonlinearity considerably. This obviously suggests the potentiality of the crystal as an optical power limiter and also for various optical device applications.

36 MATERIALS SCIENCE↗
DOE OSTI2014

EPR and optical investigations of LaMgAl{sub 11}O{sub 19}:Cr{sup 3+} phosphor

Graphical abstract: The EPR spectrum of as-prepared LaMgAl{sub 11}O{sub 19}:Cr{sup 3+} phosphor at 110 K. - Highlights: • Using the combustion synthesis, LaMgAl{sub 11}O{sub 19}:Cr{sup 3+} phosphor has been prepared in a few minutes. • Optical investigation indicates that Cr{sup 3+} ions are present in octahedral symmetry. • The EPR signals indicate that exchange coupled Cr{sup 3+}–Cr{sup 3+} ion pairs in weakly distorted sites. - Abstract: The LaMgAl{sub 11}O{sub 19}:Cr{sup 3+} phosphor has been prepared by a low-temperature combustion synthesis method. As-prepared combustion synthesized powder was characterized using powder X-ray diffraction (XRD), diffuse reflectance (DRS), electron paramagnetic resonance (EPR) and photoluminescence (PL) studies. The X-ray diffraction pattern reveals crystalline hexagonal phases. The UV–vis diffuse reflectance spectrum exhibits three broad bands characteristic of Cr{sup 3+} ions in octahedral symmetry. The EPR spectrum exhibits several resonance signals. The signals with the effective g values at g = 4.84, 3.64 and 2.26 have been attributed to the isolated Cr{sup 3+} ions. The signal with the effective g value at g = 1.94 has been attributed to exchange coupled Cr{sup 3+}–Cr{sup 3+} ion pairs. The PL studies exhibit several bands characteristic of Cr{sup 3+} ions in octahedral symmetry.

36 MATERIALS SCIENCE↗
DOE OSTI2015

Photocatalytic property and structural stability of CuAl-based layered double hydroxides

Three types of CuMAl layered double hydroxides (LDHs, M=Mg, Zn, Ni) were successfully synthesized by coprecipitation. Powder X-ray diffraction (XRD), inductively coupled plasma atomic emission spectrometry (ICP-AES) and UV–Vis diffuse reflectance spectrum (UV–vis) were used to confirm the formation of as-synthesized solids with good crystal structure. The photocatalytic activity of those LDH materials for CO{sub 2} reduction under visible light was investigated. The experimental results show that CuNiAl-LDHs with narrowest band gap and largest surface areas behave highest efficiency for methanol generation under visible light compared with CuMgAl-LDHs and CuZnAl-LDHs. The CuNiAL-LDH showed high yield for methanol production i.e. 0.210 mmol/g h, which was high efficient. In addition, the influence of the different M{sup 2+} on the structures and stability of the CuMAl-LDHs was also investigated by analyzing the geometric parameters, electronic arrangement, charge populations, hydrogen-bonding, and binding energies by density functional theory (DFT) analysis. The theoretical calculation results show that the chemical stability of LDH materials followed the order of CuMgAl-LDHs>CuZnAl-LDHs>CuNiAl-LDHs, which is just opposite with the photocatalytic activity and band gaps of three materials. - Graphical abstract: The host–guest calculation models and XRD patterns of CuMAl-LDHs: CuMgAl-LDHs (a), CuZnAl-LDHs (b) and CuNiAl-LDHs (c). - Highlights: • Three types of CuMAl layered double hydroxides (LDHs, M=Mg, Zn, Ni) has been synthesized. • CuMgNi shows narrower band gap and more excellent textural properties than other LDHs. • The band gap: CuMgAl<CuZnAl<CuNiAl based on result from UV–vis analysis. • CuMgAl shows the highest stability and lowest photocatalytic activity, while CuNiAl just opposite.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2014

Thermal equation of state of solid naphthalene to 13 GPa and 773 K: In situ X-ray diffraction study and first principles calculations

In a wide range of P-T conditions, such fundamental characteristics as compressibility and thermoelastic properties remain unknown for most classes of organic compounds. Here we attempt to clarify this issue by the example of naphthalene as a model representative of polycyclic aromatic hydrocarbons (PAHs). The elastic behavior of solid naphthalene was studied by in situ synchrotron powder X-ray diffraction up to 13 GPa and 773 K and first principles computations to 20 GPa and 773 K. Fitting of the P-V experimental data to Vinet equation of state yielded T 0 = 8.4(3) GPa and T' = 7.2 (3) at V0 = 361 Å(3), whereas the thermal expansion coefficient was found to be extremely low at P > 3 GPa (about 10(-5) K(-1)), in agreement with theoretical estimation. Such a diminishing of thermal effects with the pressure increase clearly demonstrates a specific feature of the high-pressure behavior of molecular crystals like PAHs, associated with a low energy of intermolecular interactions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

Investigations on spectral and dielectric properties of semi-organic single crystal – morpholinium nitrate

Semi organic nonlinear optical crystal Morpholinium nitrate (MN) was synthesized and subsequently grown from the solution by slow evaporation method. The sample has been subjected to powder X-ray diffraction to identify the crystalline nature and the prominent peaks were indexed. The crystal belongs to the monoclinic system with a space group P2{sub 1}/C. Carbon NMR analysis confirms the presence of carbon in the structure of the title compound. Dielectric studies have been carried out on the grown crystal as a function of frequencies at different temperatures. Dielectric constant, dielectric loss and AC conductivity were also calculated.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2015

Near room temperature giant magnetodielectricity in BiFeO{sub 3}/CoFe{sub 2}O{sub 4} composite

Here we report near room temperature giant magnetodielectric observed in BiFeO{sub 3}/CoFe{sub 2}O{sub 4} composite. This composite is prepared in slightly un-conventional method involving sol-gel auto combustion route. Phase purity has been confirmed by Reitweld refinement of powder x-ray diffraction data. Highest magnetodielectric (in %) of 62% is seen at 320K. Most interesting, in the temperature range (300 – 350K) of measurement, magnetodielectric has not gone below 50%.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2013

Design and construction of porous metal-organic frameworks based on flexible BPH pillars

Three metal-organic frameworks (MOFs), [Co{sub 2}(BPDC){sub 2}(4-BPH){center_dot}3DMF]{sub n} (1), [Cd{sub 2}(BPDC){sub 2}(4-BPH){sub 2}{center_dot}2DMF]{sub n} (2) and [Ni{sub 2}(BDC){sub 2}(3-BPH){sub 2} (H{sub 2}O){center_dot}4DMF]{sub n} (3) (H{sub 2}BPDC=biphenyl-4,4 Prime -dicarboxylic acid, H{sub 2}BDC=terephthalic acid, BPH=bis(pyridinylethylidene)hydrazine and DMF=N,N Prime -dimethylformamide), have been solvothermally synthesized based on the insertion of heterogeneous BPH pillars. Framework 1 has 'single-pillared' MOF-5-like motif with inner cage diameters of up to 18.6 A. Framework 2 has 'double pillared' MOF-5-like motif with cage diameters of 19.2 A while 3 has 'double pillared' 8-connected framework with channel diameters of 11.0 A. Powder X-ray diffraction (PXRD) shows that 3 is a dynamic porous framework. - Graphical abstract: By insertion of flexible BPH pillars based on 'pillaring' strategy, three metal-organic frameworks are obtained showing that the porous frameworks can be constructed in a much greater variety. Highlights: Black-Right-Pointing-Pointer Frameworks 1 and 2 have MOF-5 like motif. Black-Right-Pointing-Pointer The cube-like cages in 1 and 2 are quite large, comparable to the IRMOF-10. Black-Right-Pointing-Pointer Framework 1 is 'single-pillared' mode while 2 is 'double-pillared' mode. Black-Right-Pointing-Pointer PXRD and gas adsorption analysis show that 3 is a dynamic porous framework.

36 MATERIALS SCIENCE↗
DOE OSTI2015

Structure and physical properties of RE{sub 2}AgGe{sub 3} (RE=Ce, Pr, Nd) compounds

We have synthesized the compounds RE{sub 2}AgGe{sub 3} (RE =Ce, Pr, Nd) by arc melting. The crystal structure obtained from single crystal and powder X-ray diffraction suggests that these compounds crystallize in the α-ThSi{sub 2} structure type. The magnetic susceptibility data of Ce{sub 2}AgGe{sub 3} follows Curie–Weiss (CW) law above 25 K without any magnetic ordering down to 2 K. The effective magnetic moment (μ{sub eff}) was calculated as 2.53 μ{sub B}/Ce and negative Curie paramagnetic temperature (θ{sub p})=−2.4 K hint weak antiferromagnetic coupling among the adjacent spins. Pr{sub 2}AgGe{sub 3} shows a complex magnetic behavior wherein the magnetic susceptibility at field cooled and zero field cooled modes bifurcates at 11.5 K with the latter undergoing a cusp like maxima, probably due to weak ferromagnetic interaction. The θ{sub p} and μ{sub eff} obtained are 4 K and 4.33 μ{sub B}/Pr, respectively. Nd{sub 2}AgGe{sub 3} undergoes multiple magnetic transitions. Temperature dependent resistivity data reveals that three compounds are metallic in nature. - Graphical abstract: The compounds Ce{sub 2}AgGe{sub 3}, Pr{sub 2}AgGe{sub 3} and Nd{sub 2}AgGe{sub 3} have been synthesized by arc melting. X-ray diffraction suggests tetragonal α-ThSi{sub 2} type structure and diverse magnetic properties exhibited in the magnetic measurements. - Highlights: • Two new compounds Ce{sub 2}AgGe{sub 3}, Nd{sub 2}AgGe{sub 3} and known Pr{sub 2}AgGe{sub 3} synthesized by arc melting. • Crystal structure of the compounds derived from X-ray diffraction. • Ce{sub 2}AgGe{sub 3} and Pr{sub 2}AgGe{sub 3} exhibit antiferromagnetic ordering. • Nd{sub 2}AgGe{sub 3} shows multiple magnetic transition with ferrimagnetic like behavior.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗