Physical Property Measurement System Research Articles

Influence of plastic deformation on the microstructural and magnetic properties of some Fe-based alloys

We report the morphological and magnetic properties of deformation-induced martensite characteristics in the austenite phase of Fe69Ni27Mn4 and Fe67Ni27Mn4Zn2 (wt %) alloys after 30% plastic deformation. Scanning electron microscopy (SEM) and also physical property measurement system (PPMS) facilities were applied to investigation to clarify the deformation-induced martensite characteristics from morphological and magnetic points of view. Scanning electron microscope observations showed elongated deformation-induced martensite morphology in the austenite phase of the examined alloys. Additionally, two alloys exhibited typical ferromagnetism in their martensite phase. The saturation magnetization (Msat) was found to be firstly increased and then decreased with increasing temperature. We found that the % Zn addition shifts the Curie temperature (Tc) of Fe–Ni–Mn alloys to higher temperatures. The largest Msat (~ 27 emu·g−1), the Hc (~ 26 Oe), and Tc (~ 248) were obtained for the Fe–Ni–Mn–Zn alloy with a mixed configuration of bcc and fcc phases.

Magneto-transport of mechanically-pressed niobium carbide (Nb2C) distorted MXene

Early this decade, a new family of two-dimensional (2D) transition metal carbides/nitrides/carbonitrides, called MXenes, was discovered carrying a distinctive blend of physical properties. Herein, we report magneto-transport (MR) properties of Nb2C-MXene pellet and its electrical properties from 2 K to 300 K. We have observed its semiconducting-behavior under different applied magnetic field strength which gives rise to the magneto-transport behavior that is consistent with the resistance-temperature (R-T) trend. The measurements were performed at different temperatures (2 K–50 K) at a field strength of ±100KOe using physical property measurement system (PPMS-9, Quantum Design). In low-temperature region, the resistance of pellet increases with decrease in temperature and the negative trend in MR, both, are consistent with the weak-localization effect, a feature that exists in many low-dimensional materials. Our results present the possibility of employing MXenes in spintronic-devices for data storage purpose.

Zinc-bearing dust derived non-toxic mixed iron oxides as magnetically recyclable photo-Fenton catalyst for degradation of dye.

In this paper, comprehensive utilization of hazardous zinc-bearing dust for preparation of non-toxic mixed iron oxides as a magnetically recyclable photo-Fenton catalyst for degradation of dye by a facile solid state reaction process was proposed. The as-prepared samples were characterized by X-ray diffraction (XRD), Raman spectra, ultraviolet and visible (UV-Vis) spectra and Physical Property Measurement System (PPMS), and the degradation performance of as-prepared catalysts was also tested and analyzed. The results show that spinel ferrite coexisting with or without Fe2O3 was the predominant phase in the as-prepared samples, which were confirmed by Raman analysis. The as-prepared samples presented high degradation efficiency (about 90%) of rhodamine B (RhB) in the presence of hydrogen peroxide (H2O2) with visible light irradiation, owing to the synergistic effect of photocatalyst reaction and Fenton-like catalyst reaction during the degradation process. The mixed iron oxides also presented stable structure and exhibited excellent reusability with a degradation efficiency of 87% after the fifth cycle of reuse. Importantly, the heavy metals in the zinc-bearing dust could be fixed in the stable spinel structure. This paper could provide a simple approach for comprehensive utilization of zinc-bearing dust to synthesize non-toxic mixed iron oxides as a magnetically recyclable photo-Fenton catalyst for degradation of dye.

Experimental setup for the Seebeck and Nernst coefficient measurements.

A new experimental setup is designed for the measurement of Seebeck and Nernst coefficients on the single crystal flakes and polycrystalline samples. The setup utilizes the multifunctional probe assembly of the physical property measurement system by Quantum Design, Inc. and can measure in the temperature range of 1.8 K-380 K up to 8 T magnetic fields. The experimental measurement was fully automated through a computer using the code written in LabVIEW software. The setup is capable of measurements on samples as small as 2 × 1 mm2 in size and thickness as small as a few micrometers, which is quite important for the crystal flakes grown using the vapor transport method. The determination of the coefficients is based on the quasi-static approach, with the thermal gradient of 0.2 K-1.2 K across the sample in the measured temperature range of 1.8 K-300 K. The sensitivity of the instrument is better than 0.1 µV/K, and the accuracy is better than ∼0.5 µV/K, which can be further improved with the better quality of electrical contacts on the sample. The Seebeck and Nernst coefficient measurements performed on some well-studied semimetallic (bismuth), thermoelectric (Bi2Se3), and superconducting (FeTe0.5Se0.5) systems are also presented.

Superparamagnetic Magnetite Nanotubes Synthesized by Template-Assisted Sol–Gel Autocombustion

Magnetite nanotubes with an average diameter of about 140 nm were synthesized by an AAO templateassisted sol–gel autocombustion method. The entire synthetic process is convenient, low-cost and nontoxic. The crystalline structure of the magnetite nanotubes was investigated by X-ray diffraction. From the diffraction pattern, we conclude that pure phase magnetite nanotubes were obtained. Tubular morphologies of the products were observed by transmission electron microscope. The as-prepared magnetite nanotubes have a high aspect ratios. The magnetic properties of the nanotubes were measured by a Physical Property Measurement System. The magnetic measurements indicate that the nanotubes have superparamagnetic characteristic at room temperature, and have ferromagnetic characteristic with a coercivity of about 518 Oe at 5 K. The blocking temperature TB of the nanotubes are measured to be 95 K. The as-prepared magnetite nanotubes may find potential applications in bio-medicine.

Theoretical and experimental investigation of magnetic properties of iodine and cerium Co-doped Bi2Te3 nanoparticles

A long-range magnetic order in the topological insulator (Bi2Te3) achieved a great interest by the doping of magnetic elements on to Bi and Te-sites. The magnetic moments can be introduced by adding trivalent rare-earth elements such as Ce and I. In this report, Bi2Te3, Ce0.2Bi1.8Te3, and Ce0.2Bi1.8Te2.9I0.1 nanoparticle were synthesized by the novel low-temperature double solvent sol-gel technique. The co-doped nanoparticles were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), physical properties measurement system (PPMS), and vibrating sample measurement system (VSM). The VSM studies showed that the magnetization (M) of pure Bi2Te3 sample was successfully increased by adding iodine onto the Ce-doped sample (Ce0.2Bi1.8Te2.9I0.1). For in-depth analysis, PPMS results revealed that the as-synthesized samples exhibit paramagnetic nature which then exchange into antiferromagnetic behavior after substituting Ce I onto Bi2Te3, at a varying temperature range from 0 to 400K. The density functional theory (DFT) was also performed to understand the exchange-biased phenomenon for as-synthesized samples. Moreover, the experimental results can predict that the magnetic samples synthesized by the novel double solvent sol-gel method can provide magnetic materials with large remnant magnetization compared with the pure Bi2Te3.

Magnetic anisotropy of cobalt - palladium CoxPd100-x thin films on amorphous SiO2

Cobalt – palladium thin films with different Co:Pd ratio, CoxPd100-x (x=23, 36, 42), have been deposited on fused silica (amorphous SiO2) by pulsed laser deposition (PLD). For the structural characterization of the thin films, X-ray reflectivity (XRR) and X-ray diffraction (XRD) are used and for investigation the magnetic characteristics of the films, physical properties measurement system (PPMS) is used. The results show that the thickness of the thin films is in the range of 16-20 nm and the crystal structure of the films is FCC. Also, the films have a [111] preferred growth direction. The study of the magnetic properties shows that the magnetic anisotropy tends to align in the perpendicular direction by the increase of Pd:Co ratio, which is attributed to the enhancement of the spin-orbit interaction. Also, in this work, the effect of thickness on the magnetic anisotropy is investigated.

Magnetoresistance Behavior of Cryogenic Temperature Sensors Based on Single-Walled Carbon Nanotubes

We report on the experimental investigation of the magnetoresistance behavior of cryogenic temperature sensors based on single-walled carbon nanotubes (SWCNTs) as a function of temperature and magnetic flux density; one sensor was based on layers/networks of unsorted SWCNT of various chiralities, and one on SWCNTs layers of (7,6) chirality. SWCNT-based sensors were fabricated according to a straightforward method, and the electrical properties were measured from room temperature down to 2 K using a Quantum Design Physical Property Measurement System (PPMS). The two sensors present different magneto-transport behavior, with the magnetoresistance dependence on the magnetic field being a sum of two terms with positive and negative contributions respectively. The expression for magnetoresistance is derived together with its experimentally determined coefficients. For both sensors, the electrical resistance dependence on temperature below the 80 K mark is explained by Mott's law of variable-range hopping. The experimentally obtained hopping dimension d values of 2.67 for the system comprised of purified (7,6) chirality SWCNTs and 2.97 for the system comprised of unsorted SWCNTs are in good agreement with the theory. As a second step, the magnetic field was kept constant and at different values, while the temperature was scanned over the investigated domain.

Comparative study of tensile properties and magnetic properties for Nb-doped Fe-based wires

Herein, the comparative study of tensile and magnetic properties of Fe-based wires formed by rotated-dipping process before and after Nb-doping has been reported. In which, the phase composition, crystallization temperature, surface and fracture morphology, and magnetic performance are respectively investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscope (SEM) and Physical Property Measurement System (PPMS), respectively. Further, the experimental results indicate that the Nb-doped Fe-based wires show an amorphous state, uniform, and continuous, with excellent glass forming ability (GFA) and thermal stability. The saturation magnetization Ms and remanent magnetization Mr decrease owing to Nb-doping, while the coercivity Hc shows an increasing trend with the rising of Nb-doping, reaching 33.0 Oe. The tensile deformation process of Nb-doped Fe-based wires is mainly elastic deformation, reflecting the brittle fracture characteristics. While the Nb-doping can effectively enhance the tensile strength Rm of Fe-based wires, and the Rm of FeSiBNb3 wires exhibits the maximum value of 3.58 GPa. Moreover, the fracture morphology takes on the massive shear bands, and the fracture angles are about 45°, there are also some vein-shaped patterns and molten drops, even the fracture reliability analysis based on the statistical theory of Weibull mechanics indicates that the Nb-doped Fe-based wires possess an obviously improved fracture reliability. Therefore, it can be concluded that the Fe-based wires with improved tensile and magnetic properties as the candidates are adopted for potential electromagnetic and mechanical engineering applications.

Enhanced current carrying ability for GaBa2Cu3O7-x films deposited with negative bias by RF magnetic sputtering method

GaBa2Cu3O7−x films were prepared on LaAlO3 substrate by RF magnetic sputtering with different temperature and negative bias from 800 to 860 °C and 0 v to – 90 v, respectively. We investigate the relationship between temperature and negative bias and the performance of the film to analyze the most suitable deposition conditions. The surface texture and structure of GaBa2Cu3O7−x films were observed by X-ray diffraction (XRD), Raman measurement, field emission scanning electron microscope (FESEM). The superconducting properties were measured by physical property measurement system (PPMS). It was found that the structure, surface morphology, and superconducting property of GaBa2Cu3O7−x film are seriously affected by the temperature and negative bias. The crystallinity and surface quality of the film first increases and then decreases with the increase in the deposition temperature, and reach the best at 840 °C. In order to further improve the performance of the film, a negative bias voltage of 0 to − 90v was applied on the basis of this temperature, and the best quality film was obtained under a negative bias of – 30 v. The surface of the film prepared under the conditions of 840 °C and − 30v is the most dense and uniform, and the critical current density reaches 0.16MA/cm2, which is almost 3 times higher than that of the film prepared without negative bias.

Crystal structure and thermodynamic properties of the coordination compound calcium D-gluconate Ca[D-C6H11O7]2(s)

The coordination compound calcium D-gluconate, Ca[D-C6H11O7]2(s), was synthesized and characterized by chemical analysis, elemental analysis, and X-ray crystallography. Single crystal X-ray diffraction technique revealed that the compound was formed by two D-gluconate anions and one calcium (II) cation. And the D-gluconate anion had a curved chain configuration with an intramolecular bond. The compound exhibited an outstanding chelate property of D-gluconate anions to calcium (II) cations, and the calcium (II) cation was eight-coordinated and chelated by four D-gluconate anions. The lattice potential energy and ionic volume of the anion were calculated to be 1434.05 kJ⋅mol−1 and 0.4211 nm3 from crystallographic data. In accordance with famous Hess law, a reasonable thermochemical cycle was designed and the standard molar enthalpy of formation of Ca[D-C6H11O7]2(s) was calculated as ΔsHm[Ca[D-C6H11O7]2, s] = -(3545.19 ± 1.07) kJ⋅mol−1 by use of an isoperibol solution-reaction calorimeter. Furthermore, molar heat capacities of the compound were measured using a Quantum Design Physical Properties Measurement System (PPMS) with specific heat option within the temperature range from (1.9–300) K. The heat capacities of the compound increased with the temperature and no thermal anomaly was found in the whole temperature region. The experimental data was fitted to a function of the absolute temperature T with a series of theoretical and empirical models for the proper temperature ranges. The values of standard thermodynamic function, Cp,mo/J⋅K−1⋅mol−1, Δ0THmo/kJ⋅mol−1, Δ0TSmo/J⋅K−1⋅mol−1, and ΔoTGmo/T/J⋅K−1⋅mol−1 (=Δ0TSmo-Δ0THmo/T) from T = (0–300) K was calculated based on the fitting results. The standard molar heat capacity, entropy and enthalpy of the compound at T = 298.15 K and 0.1 MPa was determined to be Cp,mo= (493.20 ± 2.70) J·K−1 mol−1, Hmo= (75934 ± 805) J·mol−1, Smo= (471.55 ± 2.78) J·K−1 mol−1, and Gmo/T = - (64658 ± 808) J·K−1⋅mol−1, respectively.

Temperature-dependent Gilbert damping in Co2 FeAl thin films with different B2 ordering degrees* *Project supported by the National Natural Science Foundation of China (Grant Nos. 51671099, 11974149, and 51901163) and the Program for Changjiang Scholars and Innovative Research Team in University, China (Grant No. IRT-16R35).

The temperature-dependent Gilbert damping in Co2FeAl thin film grown on a Pb(Mg1/3Nb2/3)O3-30%PbTiO3 substrate is investigated by the systematic measurement of physical property measurement system (PPMS) on a series of samples with different substrate temperatures. Varying the substrate temperatures from 350 °C to 500 °C, the B2 ordering degrees of Co2FeAl thin films increase, which can lead the Gilbert damping to decrease, indicated by the field-sweep in-plane PPMS measurements. In addition, the measurement result of PPMS demonstrates that the Gilbert damping decreases first with measurement temperature decreasing down to about 150 K, then increases at a measurement temperature of ∼ 50 K, and decreases again with the measurement temperature decreasing. There are two independent damping manners, namely bulk damping and surface damping, which contribute to the Gilbert damping. Moreover, the observed peak of Gilbert damping at ∼ 50 K can be attributed to the spin re-orientation transition at the Co2FeAl surface, which is similar to the result of the effective magnetization as a function of measurement temperature. The result presents the evidence for further studying the Gilbert damping in Co2FeAl thin film.

Law of Approach to Magnetic Saturation in Nanocrystalline Pr2Co7Cx(x≤1): Effects of Carbonation

We report on the effect of Carbon insertion on the microstructure and magnetic properties of nanocrystalline Pr2Co7Cx([Formula: see text]). The Pr2Co7Cx were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and physical property measurement system (PPMS9) Quantum Design. Mean field theory was utilized to depict the temperature dependence of magnetization and deduce the exchange interactions. The approach to saturation magnetization was as well used. The results were interpreted in the framework of random magnetic anisotropy model. From such analysis, some fundamental parameters were extracted.

The surprising thermal properties of CM carbonaceous chondrites

AbstractMeasurements of the low‐temperature thermodynamic and physical properties of meteorites provide fundamental data for the study and understanding of asteroids and other small bodies. Of particular interest are the CM carbonaceous chondrites, which represent a class of primitive meteorites that record substantial chemical information concerning the evolution of volatile‐rich materials in the early solar system. Most CM chondrites are petrographic type 2 and contain anhydrous minerals such as olivine and pyroxene, along with abundant hydrous phyllosilicates contained in the meteorite matrix interspersed between the chondrules. Using a Quantum Design Physical Property Measurement System, we have measured the thermal conductivity, heat capacity, and thermal expansion of five CM2 carbonaceous chondrites (Murchison, Murray, Cold Bokkeveld, Northwest Africa 7309, Jbilet Winselwan) at low temperatures (5–300 K) which span the range of possible surface temperatures in the asteroid belt and outer solar system. The thermal expansion measurements show a substantial and unexpected decrease in CM2 volume as temperature increases from 210 to 240 K followed by a rapid increase in CM2 volume as temperature rises from 240 to 300 K. This transition has not been seen in anhydrous CV or CO carbonaceous chondrites. Thermal diffusivity and thermal inertia as a function of temperature are calculated from measurements of density, thermal conductivity, and heat capacity. Our thermal diffusivity results compare well with previous estimates for similar meteorites, where conductivity was derived from diffusivity measurements and modeled heat capacities; our new values are of higher precision and cover a wider range of temperatures.

Trilayer Films of YBa2Cu3O7−x/LaAlO3/YBa2Cu3O7−x with Superconducting Properties Prepared via Sol-Gel Method

The YBa2Cu3O7−x/LaAlO3/YBa2Cu3O7−x (YBCO/LAO/YBCO) heterogeneous trilayer film structures were prepared on the LaAlO3 (001) single-crystal substrate via the sol-gel method. The characteristics of the phase, orientation, and superconducting properties were studied via an X-ray diffractometer and a comprehensive physical property measurement system. The results show that when the LAO layer was thin (<40 nm), the trilayer films were relatively pure and had a high c-axis orientation. When the nominal thickness of the LAO layer increased to 70 nm, non-c-axis oriented grains started to appear in the trilayer film. In this case, the top and bottom YBCO layers exhibited superconducting properties, and the resistance was found to be zero at 80.1 and 72.5 K, respectively. In addition, for the YBCO/LAO (40 nm)/YBCO structure, the intermediate LAO layer was too thin to completely cover the surface of the underlying YBCO. This resulted in point contact and micro-bridge contact in several micro-regions, thus forming a weak connection and exhibiting a current-voltage (I–V) characteristic similar to the direct-current (DC) Josephson effect. On the other hand, for the YBCO/LAO (70 nm)/YBCO structure, the thicker LAO layer could completely cover the underlying YBCO surface, which could isolate the superconducting current between the YBCO layers.

Vibrational heat capacity of silver carp collagen

The study of the experimental and calculated heat capacity, Cp of fish collagen (silver carp) with contents of several additive components was presented. The experimental low-temperature heat capacity was measured in the temperature range of 1.85 to 302.8 K using a Quantum Design Physical Property Measurement System (PPMS) and the higher temperature Cp from 223.15 K to 382.15 K by Differential Scanning Calorimetry (DSC) method. For an interpretation of the experimental, low-temperature data, the vibrational heat capacity of the pure silver carp collagen was calculated based on the contribution of a sum of the vibrational heat capacity of 4248 amino acids. The vibrational heat capacity for each amino acids was taken from Advanced Thermal Analysis System (ATHAS) Data Bank for individual poly (amino acid) residues based on their group and skeletal vibrational spectra. Comparing of the experimental heat capacity of the collagen with additive components and the calculated vibrational heat capacity of the pure silver carp collagen shows that the differences range from around 10% at 100 K to 14% at 300 K temperature. Such thermal analysis can provide information about the contribution to Cp of unknown components or impurities in the investigated system.

The elastic, magnetic, and electrical properties of Sr1–уYуCoO3–x cobaltites in the composition range 0.2 ≤ y ≤ 0.3

Anion-deficient layered cobaltites Sr0.75Ln0.25CoO3–x (Ln is a lanthanide) have attracted the special attention of the scientists who study the nature of phase transformations in perovskite-like cobaltites, the anomalous behavior of the temperature magnetization of which is still the subject of scientific discussion. The purpose of this work is to investigate the regularity of changes in the elastic, magnetic, and electrical properties of layered cobaltites Sr1–уYуCoO3–x in the composition range 0.2 ≤ y ≤ 0.3 over a wide temperature range. The studied polycrystalline samples were obtained by the known ceramic technology in the air. Electron microscopic studies were performed on a LEO 1455 PV scanning electron microscope. The temperature dependence of the Young’s modulus was studied by the method of resonance vibrations in the frequency range 1000–6000 Hz and in the temperature range 100–450 K. X-ray phase analysis was performed on a DRON-3M diffractometer under Cu-Kα radiation. Magnetic measurements were performed using a physical property measurement system (Cryogenic Ltd.) in the temperature range 5–325 K. As a result of the studies, it was found that in the temperature range 25–300 K, Sr1–уYуCoO3–x solid solutions (0.2 ≤ y ≤ 0.3) are characterized by the semiconductor-like conductivity. No significant magnetoresistive effect was observed in this temperature range for the studied compositions. It was shown that the Sr1–уYуCoO3–x solid solution (у = 0.25) exhibits two magnetic phase transformations: low-temperature near 220 K and high-temperature at 350 K. The nearby compositions of the concentration range 0.2 ≤ y ≤ 0.3 exhibit magnetic phase transformations at temperatures above room temperature. No low-temperature phase transitions were detected in them. It has been established that magnetic phase transformations are accompanied by structural transitions at corresponding temperatures.

Super-Necking Crystal Growth and Structural and Magnetic Properties of SrTb2O4 Single Crystals.

We report on single-crystal growths of the SrTb2O4 compound by a super-necking technique with a laser-floating-zone furnace and study the stoichiometry, growth mode, and structural and magnetic properties by scanning electronic microscopy, neutron Laue, X-ray powder diffraction, and the physical property measurement system. We optimized the growth parameters, mainly the growth speed, atmosphere, and the addition of a Tb4O7 raw material. Neutron Laue diffraction displays the characteristic feature of a single crystal. Our study reveals an atomic ratio of Sr:Tb = 0.97(2):2.00(1) and a possible layer by layer crystal growth mode. Our X-ray powder diffraction study determines the crystal structure, lattice constants, and atomic positions. The paramagnetic (PM) Curie–Weiss (CW) temperature θCW = 5.00(4) K, and the effective PM moment Mmeaeff = 10.97(1) μB per Tb3+ ion. The data of magnetization versus temperature can be divided into three regimes, showing a coexistence of antiferromagnetic and ferromagnetic interactions. This probably leads to the magnetic frustration in the SrTb2O4 compound. The magnetization at 2 K and 14 T originates from both the Tb1 and Tb2 sites and is strongly frustrated with an expected saturation field at ∼41.5 T, displaying an intricate phase diagram with three ranges.

Influence of Tm–Tb substitution on magnetic and optical properties of Ba–Sr hexaferrites prepared by ultrasonic assisted citrate sol-gel approach

Tm–Tb co-substituted Sr–Ba hexaferrite (HFs), Sr0.5Ba0.5TmxTbxFe12-2xO19 (x = 0.00–0.05), were produced by ultrasonic assisted citrate sol-gel approach. The compositions were characterized using diverse characterization techniques including X-rays diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning and transmission electron microscopes (SEM and TEM), diffuse reflectance spectroscopy (DRS), and physical property measurement system with vibrating sample magnetometer head (PPMS-VSM). All products are pure and consist of only hexaferrite phase except x = 0.05 composition, which contains minor impurity Fe2O3 phase. Co-doping of Tm3+ and Tb3+ ions increases the 1.73 eV band gap of Sr0.5Ba0.5Fe12O19 to maximum value of 2.65 eV belonging Sr0.5Ba0.5Tm0.03Tb0.03Fe11.94O19 HF. The magnetic properties were investigated at 300 K (RT) and 10 K. Magnetization measurements indicated ferrimagnetic behaviors for different prepared hexaferrites. It was noticed that the Ms (saturation magnetization) and Mr (remanence) grew with rising Tb–Tm co-substitution proportion up to x = 0.03 and then started decreasing. The intensification in the Ms and Mr values up to x = 0.03 was mainly ascribed to the magnetic moments of Tb3+ ions (9.7 μB) and Tm3+ ions (7.5 μB) that are superior than that of Fe3+ ions (5 μB) and to strengthening of exchange coupling among Fe sites. At higher co-substitution contents, the formation of impurity phase resulted in reducing the magnetization. The coercivity is larger for lower Tb–Tm co-substitution level compared to non-substituted one and reduced for highest level. It was revealed that the coercivity is mainly dominated by the magneto-crystalline anisotropy in different prepared hexaferrites. The examination of M-T curves showed ferrimagnetic behavior in the whole temperature range of 325 down to 10K and the existence of super-spin glass-like behavior at very low temperatures.

Low-temperature heat capacity of d-glucose and d-fructose

The thermodynamics data of crystalline states of two representative components in blood sugar, d-glucose and d-fructose, are significant in researching artificial synthesis and composition transformation in vivo. The heat capacities of d-glucose and d-fructose over a temperature range of 1.9–300 K were measured and calculated by the heat capacity measurement module of physical property measurement system (PPMS). The heat capacities of two compounds increased steadily with temperature, showing a smooth curve without any thermal anomalies. The heat capacity of d-glucose is greater than that of d-fructose in the range of 0 K < T < 80 K, which is smaller than that of d-fructose between 80 and 300 K. Based on the lattice vibration mode, factors of generating the difference heat capacity data between the two isomers were investigated. Additionally, the heat capacity data were fitted by low-temperature heat capacity theoretical model. The thermodynamic data that molar entropy change and molar enthalpy change over the temperature range of 0–300 K were calculated. The standard molar entropy of d-glucose and d-fructose at 298.15 K was calculated by heat capacity fitting to be 214.64 and 217.56 J K−1 mol−1, all with an error of 0.21.