Space Group Immm Research Articles

Synthesis and Physico-chemical Characterization of Solid Solution (1-x)CCTO−xPbTiO3

The composite materials of (1-x)CaCu3Ti4O12, xPbTiO3((1-x)CCTO−xPT) were prepared by a modified solid-state method in several steps. The Rietveld refinement indicates the formation of the pure cubic and tetragonal phases for calcium copper titanate (CCTO) and lead-titanate (PT) pure ceramics, respectively. While for CCTO-PT composites, the coexistence of the two cubic and tetragonal phases was detected with the space group Im-3 and P4mm, respectively. The Raman spectra confirmed these phase formations. The SEM images indicated a change in grains shape from quadratic to semi-spherical with increases of PT contents and a reduce in average grains size with increase of PT content. The dielectric measurements as function of temperature showed two anomalies which exhibit a relaxation-like phenomenon and a clear diffuseness behaviour for all the samples. In addition, the conductivity of these materials decreases and the resistance of grain boundaries was found to increase with the increase of PT addition.

Giant dielectric constant, dielectric relaxations, and tunable properties of Sm2/3Cu3Ti4O12 ceramics

AbstractThe polycrystalline Sm2/3Cu3Ti4O12 (SCTO) ceramics have been prepared by solid‐state reaction. The crystallinity of the compound has been investigated by Rietveld refinement which has revealed a cubic structure with space group Im3. It is observed that at low frequencies, SCTO ceramic exhibits tremendously high values of dielectric permittivity ε′, larger than 32,000, at room temperature. Two distinct, thermally triggered, dielectric relaxations have been noted. This mechanism has been confirmed through impedance analysis of the ceramics. The complex impedance plane shows three semicircles, which confirm the existence of two dielectric relaxations in SCTO ceramics. In general, the electrical as well as dielectric behavior of SCTO ceramics are seen to be reasonably analogous to those of CaCu3Ti4O12 (CCTO) ceramics. The emergence of the enormous dielectric constant in SCTO ceramic is accredited to the combined effect of polarization both at the sample‐electrode interface as well as at the insulating grain boundary interface. The SCTO ceramics are identical to the CCTO ceramics in their structure and composition and hence, as the above results indicate, the IBLC effect mechanism, originally put forward for CCTO ceramics, is furthermore plausible to account for the mammoth values of dielectric constant in SCTO ceramics.

Two-layer compounds in rare earth-{Fe, Co, Ni, Rh, Pd, Pt}-Te systems: crystal structure and magnetic properties

The partial isothermal sections of {Gd, Ho}-Ni-Te and Gd-Co-Te systems (~40–100 ​at. % of rare earth) have been investigated at 1070 ​K by X-ray and electron microprobe analysis. The Y5Ni2Te2-type {Tb, Dy, Ho}5Fe2Te2 and {Gd, Tb, Dy, Ho}5{Co, Ni}2Te2 (space group Cmcm, No. 63, oC36), Er7Ni2Te2-type Er7Co2Te2, {Y, Dy, Ho}7Ni2Te2, Ho7{Rh, Pd}2Te2 and {Y, Gd}7Pt2Te2 (space group Imm2, No. 44, oI22), Fe2P-type Ho6NiTe2 (space group P-62m, No. 189, hP9) and Sc6PdTe2-type Ho6{Rh, Pd}Te2 and {Y, Gd}6PtTe2 (space group Pnma, No. 62, oP36) compounds have been established using powder X-ray diffraction studies. Magnetization measurements show that the Y5Ni2Te2-type {Tb, Dy, Ho}5Fe2Te2, {Gd, Tb, Dy}5Co2Te2 and {Tb, Ho}5Ni2Te2 compounds exhibit a high-temperature ferromagnetic ordering with low-temperature spin-reorientation transition for Tb-, Dy- and Ho-containing compounds. Below Curie temperature, Tb5Fe2Te2, Tb5Co2Te2 and Ho5Ni2Te2 are soft ferromagnets, while they show hard magnetic properties below spin-reorientation transition. At 2 ​K, Tb5Co2Te2 and Tb5Fe2Te2 exhibit a coercive field of 35 ​kOe and ~30 ​kOe and the residual magnetization of 17.2 μB and 22.9 μB per formula unit, leading to theoretical maximum energy product of ~620 ​kJ/m3 and ~700 ​kJ/m3, respectively. Ho5Ni2Te2 reaches a maximum magnetic entropy change of −10.0 ​J/kg⋅K and −9.4 ​J/kg⋅K for a magnetic field change of 0–50 ​kOe ​at 45 ​K and 20 ​K, respectively.

The first bismuth borate oxyiodide, Bi4BO7I: commensurate or incommensurate?

The first bismuth borate oxyiodide, Bi4BO7I, has been prepared by solid-state reaction in evacuated silica ampoules. Its crystal structure [space group Immm(00γ)000] comprises litharge-related layers of edge-sharing OBi4 tetrahedra; the interlayer space is filled by I- and [BO3]3- anions. The wavevector, q= 0.242 (3)c*, is very close to the rational value of c*/4, yet refinement based on commensurate modulation faces serious problems indicating the incommensurate nature of the modulation. The I-/[BO3]3- anions are ordered in a complex sequence along [001], i.e. -<-BO3-BO3-I-I->n=28-I-I-I-<-BO3-BO3-I-I->n= 28-BO3-BO3-BO3-, leading to a structural modulation. The principal feature of the latter is the presence of -I-I-I- and -BO3-BO3-BO3- sequences that cannot be accounted for in the a× b× 4c supercell. The thermal expansion of Bi4BO7I is weakly anisotropic (αa= 8, αb= 15 and αc= 17× 10-6 K-1 at 500 K) which is caused by preferential orientation of the borate groups.

La2Ga3O7.5: A Metastable Ternary Melilite with a Super-Excess of Interstitial Oxide Ions Synthesized by Direct Crystallization of the Melt

The La1+xAE1-xGa3O7+x/2 melilite family (AE = Ca, Sr, Ba, and 0 0.65 with very high Oint concentrations (referred to here as compositions) have the potential to support correspondingly high ionic conductivities, but have never before been accessed due to the limitations of conventional solid-state ceramic synthesis. Here we report that fully-substituted La2Ga3O7.5 (x = 1) melilite ceramics can be synthesized by direct crys-tallization of an under-cooled melt, demonstrating that super-excess compositions are accessible under suitable nonequilibrium reaction conditions. La2Ga3O7.5 is stable up to 830 °C and exhibits an ionic conductivity of 0.01 S.cm-1 at 800 °C, three orders of magnitude higher than the corresponding x = 0 end-member LaSrGa3O7, and close to the range exhibited by the current best-in-class La1.54Sr0.46Ga3O7.23 (0.1 S.cm-1). It crystallizes in an orthorhombic √2a x √2a x 2c expansion of the parent melilite cell, in space group Ima2, with full long-range ordering of Oint into chains within the [Ga3O7.5] layers. The emergence of this chain-like (1D) ordering within the 2D melilite framework, which appears to be an incipient feature of previously reported partially-ordered melilites, is explained in terms of the underlying hexagonal topology of the structure. These results will enable the exploration of extended com-positional ranges for the development of new solid oxide ion electrolytes with high concentrations of interstitial oxide charge carriers.

Phase transitions in RbPrNb2O7, a layer structured ferroelectric with a high Curie point

The development of lead-free ferroelectric ceramics exhibiting a high Curie point is regarded as a key aspect of improving the overall performance of high temperature sensing devices. Two-layer Dion-Jacobson phases have great potential for these applications, but the dielectric properties of many of these compounds have not been investigated and several are still erroneously considered to be non-polar. RbPrNb2O7, a two-layer Dion-Jacobson phase, has previously been identified as being non-polar at room temperature, with an orthorhombic crystal structure in space group Imma. Here, the structure of RbPrNb2O7 is re-examined and its ferroelectric (FE) character confirmed through ferroelectric, dielectric and piezoelectric measurements, using dense bulk ceramics. In addition, the microstructure and phase evolution of the compound were analysed by transmission electron microscopy, variable temperature X-ray powder diffraction and differential scanning calorimetry. RbPrNb2O7 is a ferroelectric at room temperature, exhibiting orthorhombic symmetry in space group I2cm. It undergoes a reversible FE ↔ FE phase transition at around 260 °C, with evidence for a diffuse apolar transition between 800 and 900 °C. Details of the subtle structural changes occurring at these transitions are discussed. RbPrNb2O7 possesses a high Curie point of ~1090 °C, making it a potential candidate for use in high temperature piezoelectric sensing.

Higher temperature order–disorder transition, electrical and optical properties of [N(C2H5)4]2Pd2Cl6compound

[N(C2H5)4]2Pd2Cl6hybrid compound with semiconducting character was synthetized and characterized by X‐ray diffraction, the thermal, optical and electrical properties. X‐ray diffraction indicates that the compound crystallize at room temperature in the orthorhombic system and (Immm) space group. Two endothermic peaks at, 343 K and 440 K were observed in the DSC measurements corresponding to the evaporation of water molecules and order‐disorder transition, respectively. The optical band gap (Eg= 4.34 eV) was deduced by the Tauc relation. The electrical properties was studied using the impedance spectroscopy in the frequency range of 0.1 Hz to 1 MHz and over the temperature range of 270 K to 480 K. The analysis of Nyquist plots revealed the presence of grains, grain boundaries and the electrode effects. The equivalent circuit was determined. The Ac conductivity was analyzed by the Jonsher low and the conduction mechanism was deduced based in the Elliot theory and indicate that the correlated barrier hopping model (CBH) was described the two regions II and IV and the overlapping polaron model (OLPT) the right model described the conduction in the regions I and III.

Structure and infrared reflectivity spectra of novel Mg3Ga2GeO8 microwave dielectric ceramic with high Q

Mg3Ga2GeO8 ceramics were synthesised by means of the high-temperature solid-state reaction method. The Mg3Ga2GeO8 ceramics of the orthorhombic structure type comprised an Imma space group composed of three different octahedrons and one tetrahedron. The dense ceramic was obtained at 1340 °C and presented excellent microwave dielectric performances, namely, low εr = 9.41, high Q × f = 133, 113 GHz, and τf = −63.54 ppm/°C. The intrinsic microwave dielectric performances were analysed on the basis of the packing fraction, octahedron distortion, and infrared reflectivity spectra of the Mg3Ga2GeO8 ceramics. These merits render the Mg3Ga2GeO8 ceramics an appropriate candidate for millimetre-wave frequencies.

Colossal dielectric response and relaxation behavior in novel system of Zr4+ and Nb5+ co-substituted CaCu3Ti4O12 ceramics

In this work, we developed a novel system of isovalent Zr4+ and donor Nb5+ co-doped CaCu3Ti4O12 (CCTO) ceramics to enhance dielectric response. The influences of Zr4+ and Nb5+ co-substituting on the colossal dielectric response and relaxation behavior of the CCTO ceramics fabricated by a conventional solid-phase synthesis method were investigated methodically. Co-doping of Zr4+ and Nb5+ ions leads to a significant reduction in grain size for the CCTO ceramics sintered at 1060 °C for 10 h. XRD and Raman results of the CaCu3Ti3.8-xZrxNb0.2O12 (CCTZNO) ceramics show a cubic perovskite structure with space group Im-3. The first principle calculation result exhibits a better thermodynamic stability of the CCTO structure co-doped with Zr4+ and Nb5+ ions than that of single-doped with Zr4+ or Nb5+ ion. Interestingly, the CCTZNO ceramics exhibit greatly improved dielectric constant (~105) at a frequency range of 102–105 Hz and at a temperature range of 20–210 °C, indicating a giant dielectric response within broader frequency and temperature ranges. The dielectric properties of CCTZNO ceramics were analyzed from the viewpoints of defect-dipole effect and internal barrier layer capacitance (IBLC) model. Accordingly, the immensely enhanced dielectric response is primarily ascribed to the complex defect dipoles associated with oxygen vacancies by co-doping Zr4+ and Nb5+ ions into CCTO structure. In addition, the obvious dielectric relaxation behavior has been found in CCTZNO ceramics, and the relaxation process in middle frequency regions is attributed to the grain boundary response confirmed by complex impedance spectroscopy and electric modulus.

Synthesis and Magnetic Properties of the Ternary Oxofluoride Fe3Sb4O6F6

The new compound Fe3Sb4O6F6 was prepared by hydrothermal synthesis and its crystal structure was determined from single‐crystal X‐ray diffraction data. The synthesis was made under slightly basic conditions to prevent oxidation of Fe2+ to Fe3+. The compound crystallizes in the cubic space group I‐43m with separate crystallographic sites for Fe2+ and Sb3+. Fe3Sb4O6F6 is isostructural with M3Sb4O6F6 (M = Co, Ni, Zn). The crystal structure is comprising distorted [FeO2F4] octahedra connected via corner sharing at F‐atoms and [SbO3] trigonal pyramids that form [Sb4O6] units that connect via O‐atoms to the Fe‐atoms. Mössbauer spectroscopy measurements on the hydrothermal synthesis products prove the majority phase contains Fe in the oxidation state +2. Powder X‐ray diffraction suggests that an additional phase of the Mössbauer sample containing Fe3+ can be attributed to FeSbO2F2 as secondary phase. Fe3Sb4O6F6 exhibits antiferromagnetic order below ca. 72 K succeeded by a second magnetic phase transition at ca. 30 K. Strong antiferromagnetic spin‐exchange interaction is attributed to 180° Fe–F–Fe superexchange pathways identified in the crystal structure.

Intra- and Interchain Interactions in (Cu1/2Au1/2)CN, (Ag1/2Au1/2)CN, and (Cu1/3Ag1/3Au1/3)CN and Their Effect on One-, Two-, and Three-Dimensional Order.

Mixed-metal cyanides (Cu1/2Au1/2)CN, (Ag1/2Au1/2)CN, and (Cu1/3Ag1/3Au1/3)CN adopt an AuCN-type structure in which metal-cyanide chains pack on a hexagonal lattice with metal atoms arranged in sheets. The interactions between and within the metal-cyanide chains are investigated using density functional theory (DFT) calculations, 13C solid-state NMR (SSNMR), and X-ray pair distribution function (PDF) measurements. Long-range metal and cyanide order is found within the chains: (−Cu–NC–Au–CN−)∞, (−Ag–NC–Au–CN−)∞, and (−Cu–NC–Ag–NC–Au–CN−)∞. Although Bragg diffraction studies establish that there is no long-range order between chains, X-ray PDF results show that there is local order between chains. In (Cu1/2Au1/2)CN and (Ag1/2Au1/2)CN, there is a preference for unlike metal atoms occurring as nearest neighbors within the metal sheets. A general mathematical proof shows that the maximum average number of heterometallic nearest-neighbor interactions on a hexagonal lattice with two types of metal atoms is four. Calculated energies of periodic structural models show that those with four unlike nearest neighbors are most favorable. Of these, models in space group Immm give the best fits to the X-ray PDF data out to 8 Å, providing good descriptions of the short- and medium-range structures. This result shows that interactions beyond those of nearest neighbors must be considered when determining the structures of these materials. Such interactions are also important in (Cu1/3Ag1/3Au1/3)CN, leading to the adoption of a structure in Pmm2 containing mixed Cu–Au and Ag-only sheets arranged to maximize the numbers of Cu···Au nearest- and next-nearest-neighbor interactions.

Elastic anisotropy, electronic and magnetic behaviours of ferromagnetic Europium Niobate EuNbO3 in orthorhombic structure: DFT + U, MFA and QTAIM studies

ABSTRACT Recently, previous studies have shown that at room temperature, EuNbO3 adopts an orthorhombic structure of Imma space group with a ferromagnetic behaviour. The relevant idea of ⁣this work is to provide a new insight into some electronic and magnetic behaviours of EuNbO3 in orthorhombic structure, which are still unknown, based on the results already found previously. The structural properties have been determined using two functionals (GGA-PBE and GGA-PBEsol) and the found results are in good agreement with the previous ones. Mechanical behaviour and elastic anisotropy have also been studied in detail from which, it has been confirmed that EuNbO3 is mechanically stable in Imma orthorhombic perovskite structure. The directional analysis of Young’s modulus has shown that it is elastically anisotropic. For the electronic properties, many approaches have been used in order to take all the considerations that are not taken into account by GGA semilocal functional, hence, spin–orbit coupling effect (SOC), Hubbard correction (GGA + U) and Modified Becke–Johnson exchange potential (mBJ) have been adopted. The two adopted mBJ parameterizations gave different results, hence, for that of TB-mBJ, the studied compound is almost halfmetallic, while that of Radi A. Jishi et al. showed a semiconductor behaviour. To estimate Curie temperature, we have employed the mean field approximation (MFA), hence, its estimated value is higher than that of transition to the tetragonal I4/mcm structure, which has been determined previously. The ionic character of Eu-O and Nb-O bonds has been confirmed by The Quantum Theory of Atoms in Molecules (QTAIM).

La6Pd2+xSb15 (x = 0.28): A rare-earth palladium intermetallic compound with extended pnictogen ribbons

A new intermetallic ternary compound La6Pd2.28Sb15 was synthesized from the reaction of lanthanum and palladium metals in a molten antimony flux. The compound crystallizes in the orthorhombic space group Immm with a ​= ​4.3082(9) Å, b ​= ​15.399(3) Å and c ​= ​19.689(4) Å. The crystal structure contains a three-dimensional framework of Sb squares and ribbons that extend along the a axis, including complex Sb–Sb bonding. La6Pd2.28Sb15 is diamagnetic, with a magnetic susceptibility weakly dependent on temperature (T). The resistivity (ρ) decreases when lowering the temperature, indicating metallic behavior, and at low temperatures ρ depends quadratically on T. Interestingly, both the Hall resistivity and magnetoresistance present a nonlinear dependence on the applied magnetic field, suggesting a multiband behavior. This is supported by density-functional electronic structure calculations which show a complex Fermi surface originated in the antimonide substructures and containing both electron and hole pockets as well as open sheets.

From Zintl to Wade: Ba3LiGa5 – A Structure Pattern with Pyramidal Cluster Chains –[Ga5]n–

Investigation of the correlation between the crystal structure, electronegativity difference and valence electron concentration in intermetallic gallides lead to the discovery of the new compound Ba3LiGa5 (space group Immm, a = 6.2720(2) Å, b = 6.5872(2) Å, c = 12.6878(8) Å). A combination of quantum chemical bonding analysis with NMR study revealed the gallium substructure to be formed of chains built of the interconnected pyramidal [Ga5] clusters. Analysis of chemical bonding by means of the electron localizability approach confirmed the presence nido‐[Ga5] Wade clusters. Lithium species are not only required for the purpose of charge compensation, but also – analogous to a transition metal – occupies partially the same crystallographic position as gallium.

Synergistic Influence of d0 (Nb5+) and d10 (Cd2+) Cations in Stabilizing Noncentrosymmetric Dion-Jacobson Layered Perovskites, A'Cd2Nb3O10 (A' = Rb, Cs).

New Dion-Jacobson (n = 3) layered perovskites, A'Cd2Nb3O10 (A' = Rb, Cs), have been synthesized by a solid-state method. Powder X-ray diffraction measurements confirm the noncentrosymmetric orthorhombic (space group Ima2) structures for both rubidium- and cesium-containing layered oxides. The distorted octahedral coordination of the d0 metal cations (Nb5+) coupled with the increased covalency in the lattice by the introduction of d10 metal cations (Cd2+) is responsible for the acentric structures. The resulting second-harmonic-generation (SHG) efficiencies of the polycrystalline samples (size 45-63 μm) using 1064 nm radiation reveal comparable values for CsCd2Nb3O10 and nearly 5 times higher output values for RbCd2Nb3O10 with respect to potassium dihydrogen phosphate. These structures were further confirmed from transmission electron microscopy and Raman spectroscopy measurements. The optical characteristics show interesting variations to the expected photocatalytic activities. Ion-exchange reactions result in the synthesis of proton- and lithium-containing oxides, which are otherwise inaccessible by direct solid-state reactions. The mobilities of the interlayer ions have also been confirmed by ionic conductivity measurements.

Magnetic and magnetocaloric properties of the equiatomic europium intermetallics EuAgZn, EuAgCd, EuPtZn and EuAuCd

The europium-based intermetallic compounds EuAgZn, EuAgCd, EuPtZn and EuAuCd were synthesized and their magnetic properties and magnetocaloric performances were systematically studied. EuAgZn and EuAgCd compounds crystallize in a KHg2-type structure belonging to space group Imma, whereas EuPtZn and EuAuCd crystallize in a TiNiSi-type structure belonging to space group Pnma. The four compounds contain stable divalent europium and order ferromagnetically with Curie temperatures of TC ~29, 27, 20 and 22 K for EuAgZn, EuAgCd, EuPtZn and EuAuCd, respectively. A considerable tunable reversible MCE can be observed accompanied by a second-order magnetic transition. For the field change of 0–2 and 0–5 T, the −ΔSΜmax values are evaluated to be 7.7, 7.2, 8.2, 8.0 and 14.9, 13.5, 15.3, 13.7 J/kgK for EuAgZn, EuAgCd, EuPtZn and EuAuCd, respectively.

Structure analysis and electrical resistivity of the high- and low-temperature phases of NaPd3Ge2 single crystal

Rod-shaped single crystals of NaPd3Ge2 with a length of ∼1 mm were grown using the self-flux method. The electrical resistivity exhibits a metal-like temperature dependence with a kink at 115 K, which is due to a structural phase transition not observed in the previous study using polycrystalline samples. The high-temperature phase of NaPd3Ge2 crystallizes in an orthorhombic structure of the space group Imma, while the low-temperature phase is isostructural to NaPd3Si2 (space group: Imm2) as determined by the single-crystal X-ray diffraction analyses at 90 K. The density of states and total energies obtained by the density functional theory calculations reveal that both phases are metallic, and the low-temperature structure is more stable.

Structural analysis and magnetic properties of lattice distortions from hexagonal to tetragonal systems in non-equilibrium Y–Fe alloys

A structural analysis model, which was specialized by space group Immm and denoted by substituting a pair of iron atoms (iron dumbbell) for rare-earth (R) elements continuously, was devised and used to treat continuous lattice distortions from hexagonal TbCu7 to tetragonal ThMn12 structures observed in non-equilibrium Y–Fe alloys. Trajectories of lattice distortions due to annealing, which were drawn on a map arranged in terms of axial ratios b∕c and b∕a, could be classified into four types according to composition ratio (T∕R) of the Y–Fe alloys. Especially, type-I distortion (with composition range of 11.5≤T∕R≤13.5) transformed from a hexagonal structure with b∕a∼1.002 to a tetragonal one with b∕a=1.000 via a structure with a large distortion, i.e., b∕a=1.008. Meanwhile, type-II distortion (with composition range of 10.5<T∕R<11.5) transformed from a hexagonal structure with b∕a∼1.001 to an orthorhombic one as close as possible to a tetragonal one. Moreover, the continuous-lattice-distortion model could bring geometric insights on structural stability and magnetic properties of not only the alloys but also previously recognized compounds with modulated-CaCu5 structures, which are configured by substituting iron dumbbells for R elements.

Phase equilibria in the Gd-Ge-Sb system at 773 K and the magnetic properties of novel compound Gd8Ge13.29Sb1.72

The isothermal section of the phase diagram of the Gd-Ge-Sb ternary system at 773 K has been studied by X-ray powder diffraction (XRPD and S-PXRD), Rietveld method, scanning electron microscopy (SEM) equipped with energy dispersive (EDS), electron probe microanalysis (EPMA) and electron diffraction (ED). The existence of nine binary compounds, Gd5Ge3, Gd5Ge4, GdGe, Gd2Ge3, Gd3Ge5, Gd5Sb3, Gd4Sb3, GdSb, Gd16Sb39, and Mn5Si3-type Gd5Ge3-0Sb0-3 (space group P63/mcm, No. 193, hP16) and Th3P4-type Gd4Ge2-0Sb1-3 (space group I-43d, No. 220, cI28) quasibinary solid solutions and ternary Gd6Ge4.3Sb11.7-type Gd6Ge4.3Sb11.7 (space group Immm, No. 71, oI46) were confirmed, while new GdGe1.69Bi0.21-type Gd8Ge13.29Sb1.72 (space group Cmcm, No. 63, oC23) was found in this work which is air- and moisture-stable over periods of long time. Gd8Ge13.29Sb1.72 exhibits field unsensitive antiferromagnetic ordering at 24 K in fields up to 60 kOe and metallic type of conductivity in the temperature range of 2–400K.

Magnetization and specific heat study on a SmCuAl3 single crystal

We report on structural and magnetic properties of a SmCuAl3 single crystal. The sample quality, phase and structure purity were investigated by means of x-ray and neutron diffraction, BSE electron microscopy and EDX analysis. The crystal structure was identified to be of a tetragonal BaNiSn3-type (space group I4mm, 107). Magnetization measurements revealed two magnetic phase transitions: from paramagnetic to ferromagnetic state at Tc = 28 K and another transition at TN = 6.6 K connected with a development of the antiferromagnetic component of magnetic moments. Both ferromagnetic and antiferromagnetic components are followed down to lowest temperature. Possible origins of the phase transition at 28 K are discussed. Paramagnetic data are well described assuming a Sm3+ ground-state-multiplet splitting in crystalline environment. Crystal field parameters are estimated and used for magnetization and specific heat calculations revealing a qualitatively good agreement with the experimental data.