Cd2 Unit 3 Lab Report

The goal of nanotechnology is to make nanostructures or nano arrays with special properties, which do not exist in their bulk or single particle types. Oxide nanoparticles can present unique physical and chemical properties, because of their limited size and a high density in their corner or edge surface sites (Fernandez-Garcia & Rodriguez 2009; Bhattacharjee et al. 2011).

As magnetite is well-researched, multiple factors influence the formation of iron oxide magnetosomes have been identified. The most important factors are the presence of oxygen, and substrates in the form of nitrogen oxides (Bazylinski 2004). MORE

Ferrofluids are nanoscopic shards of magnetic particles suspended in organic fluids or water. What are the modern potentials and applications of ferrofluids? Ferrofluids have current applications in a variety of fields and continue to have potentials for further advancements in others. With research of the first ferrofluid in 1963 by Steven Papell with N.A.S.A., ferrofluids have been used to provide advancements in the field of technology. In modern times, ferrofluids are used in speakers for their relationship with magnetism and heat; as well ferrofluids are used in computer hard drives for their unique magnetic fluidic properties. Additionally, ferrofluids have potentials in the field of bio-medical engineering, including: advancements

Magnetotactic bacteria typically mineralize iron oxide or iron sulphide magnetosomes. The iron oxide magnetosomes contain crystals of magnetite (Fe3O4) 5 and the iron sulphide magnetosomes are composed of crystals of greigite (Fe3S4) 6. Of note, magnetite is the more studied form of

In stark contrast, MCM-41 and UVM-7 show much different magnetic properties after successful incorporation into the silica pores. Notably, the χMT term for both silicas is higher than expected for magnetically isolated Ni8 molecules (such as those in UVM-11) which supports the presence of repeating Ni8 units forming [Ni8]x aggregates. χMT also reaches a maximum at a range of 3-10 K, in contrast to the Tmax = 3 K of the SMM alone where Tmax generally increases with increasing loading amount. This behavior can be rationalized due to magnetic anisotropy and/or antiferromagnetic interactions between aggregates. A proposed mechanism consists of Ni8 SMMs filling the silica pores and consequent aggregation which is mediated by deprotonated silanol groups present on the pores (Fig. 4). In turn [Ni8]x aggregates, joined by Ni-O-Ni bonds interact in a ferromagnetic manner which allows for the Ni8 monomers to undergo magnetic exchange interactions. This mechanism holds up to a point, a 100% loading amount results in packing which imposes a steric strain on the filamentous [Ni8]x and pushes the Ni-O-Ni angle towards a higher value, prompting antiferromagnetic interactions leading to a decrease in magnetic susceptibility.

The M-type hard ferrites with hexagonal crystal structure can be generally represented as (MO.6Fe2O3), where M is divalent metal including Sr, Ba, and Pb or a mixture of these [1]. The direction of magnetization in these materials cannot be changed easily to another axis so that they are referred to as hard [2]. Barium hexaferrite (BaFe12O19) as a famous M-type hard ferrite with a magnetoplumbite structure has relatively high Curie temperature, coercive force and magnetic anisotropy field, along with high chemical stability and corrosion resistivity [3].

The as-prepared pristine ZnO:P and ZnO:In3+ samples were characterized via X-ray diffraction (XRD) using Cu-Kα radiation (λ= 1.54056 Å) in the 2θ range of 20°-80° [Bruker Advanced-D8 powder X-ray diffractometer]. The scanning speed and steps were 2°/ minute and 0.02° of 2θ respectively. The XRD data were analyzed by Rietveld refinement technique using FULLPROF program to confirm the phase formation as well as to obtain the lattice parameters, space group and crystal system [2]. The microstructures and crystal structures of the nanoparticles were obtained using Transmission Electron

The addition of nanoparticles must be more effective in decreasing the dihedral angle and encouraging direct bonding in comparison to micro-particles. In the present research, this phenomenon can be explained as follows: during the sintering process the nanoparticles (Al2O3 and Fe2O3) react with the CaO in matrix leading to the formation some low melting point phase’s in a faster way. Consequently, the capillary force from the wetting liquid eliminate porosity and reduce interfacial area. Since, diffusion rates in liquid are relatively high, this phenomenon results in faster bonding and densification with its corresponding improvement in physical and mechanical properties [14]. Also, For sample contains 3 wt.% Cr2O3 nanoparticles a homogeneous microstructure composed mainly of a well-distributed phases is observed. Using energy dispersive X-ray spectroscopy analysis (EDX), as a second phase, there are two phases surrounded by the magnesia and calcia ground mass. The first one corresponds to light gray particles composed by Ca and Cr elements, as it was identified by EDS. This phase is a spinel compound found in the XRD analysis and identified as CaCr2O4. The last phase corresponds to bright grey particles composed by Mg and Cr elements (identified by the EDS technique, (Table). From the EDS and XRD analysis, this phase was confirmed

Next, the temperature dependence of magnetization M(T) curves of Mn3Cu1-xGdxN under a magnetic field of 100 Oe is shown in Figure 3. For x = 0.15, decreasing from 300 to 147 K, the ZFC and FC curves are virtually indistinguishable, and then an abrupt magnetic transition from PM to FM with a pronounced ZFC-FC irreversibility appears at a TC of ~146 K, as shown in Figure 3a. Noticeably, with a slightly increase in the Gd content from 0.15 to 0.17, the M(T) curves (Figure 3b) exhibit entirely different features, in which two magnetic transitions are clearly observed. One is the typical PM-FM phase transition located at high temperature (TC1), and the other is the FM-antiferromagnetic (AFM) transition at low temperature (TC2). Further increasing the Gd content, the TC1 shifts to high temperatures (from 164 to 239 K), while the TC2 gradually moves towards low temperature (from 118 to 99 K) as demonstrated in Figures 3c and 3d. In addition, to further verify the low-temperature magnetic features, the temperature-dependent high magnetic field magnetization was measured under 20 kOe, as shown in the insets of Figures 3a–d. Obviously, a typical AFM peak is observed from the inset as displayed in Figures 3b–d, and the decreased slope of PM-FM transition suggest that it is the second-order transition induced by Gd doping. For Mn3CuN, the structural phase transition brings a three-dimensional geometrical frustration in Mn6N octahedron 45, and then the next-nearest-neighbor (Mn–N–Mn)

X-ray powder diffraction patterns of good quality were obtained for the samples using CuKα radiation of wavelength 1.5406A0 at room temperature. The obtained X-ray diffraction patterns confirmed the formation of a single phase cubic spinel structure for the ferrite samples with a crystallite size ranging from 25-34nm as reported earlier [16]. The X-ray diffraction patterns were fitted using a Rietveld refinement procedure as shown in Fig 2 [17,18]. The fitted patterns were observed for eight peaks indexed by miller indices (220), (311), (222), (400), (422), (511) and (440), evident from the normal XRD patterns as reported earlier [16]. From the Fig 2 it is observed that sharpness in the peak is increased with an observed decrease in the width of the peak, which is the indication of the increase in particle size of the ferrite with the increase in Indium content. From the Fig 2 it is evident that observed patterns were exactly coinciding with the calculated values and the difference is very negligible. In comparison with the normal XRD patterns Rietveld patterns have shown some extra peaks of (331), (531), (422), (620), (533) and (622) which correspond to the second order impurity phase. The intensities of the impurity peaks reflect that the percentage of the impurity is negligible. From the Rietveld refinement patterns of the samples it is clear that the ferrites belong to the space group Fd3m with lattice parameter values ranging from 8.3106A0 to 8.3648A0. The values are in

The XRD results revealed the presence of magnetite nanoparticles and indicated their sizes from 30 – 40 nm (Figure 1a). SEM micrograph clearly illustrates that the magnetite nanoparticles sizes varied from 27.3– 34.62 nm (Figure 1b).

Nanomaterials are at the leading edge of the rapidly developing field of nanotechnology. Their unique size-dependent properties make these materials superior and indispensable in many areas of human activity.

Gadolinium (Gd)-doped antiperovskite compounds Mn3Cu1-xGdxN were synthesized by the conventional solid-state reaction. With increasing Gd concentration, two magnetic transitions appeared, at a high Curie temperature (TC1) corresponding to paramagnetic (PM)-ferromagnetic (FM) transition and a low temperature (TC2) ascribed to the FM-antiferromagnetic (AFM) transition. The magnetic relaxation results show the formation of a magnetic metastable state after the FM-AFM transition at low temperature (lower than TC2), forming a novel magnetic-step feature in the process from AFM to FM under a certain magnetic field.

Increasing demands for high data storage and sensing applications led the interest in the area of single phase multifunctional materials so-called ‘multiferroics’. Material with coupled ferroic order parameters such as between ferroelectric and ferromagnetic in‘mutiferroics’ provides an additional degree of freedom with ability to write through ferroelectric polarization and read the data ferromagnetically in a single device. Layered aurivilius materials provide considerable interest due to its high thermal stability and the scope it provides to tune the structure intrinsically by accommodating wide varieties of magnetic cations in order to achieve desired multiferroicity. Here we report for the first time, the direct evidence of the in-plane magnetic field induced local magnetoelectrically coupled domain nucleation, growth and switchable dynamics in epitaxial LI-CVD grown Bi6Ti3Fe1.5Mn0.5O18 single phase thin films using piezo force microscopy (PFM). SQUID magnetic measurements reveal in-plane ferromagnetic signature (Ms=205 emu/cc, Hc=170 Oe). Thorough microstructural analysis in parallel with statistical analysis, allow us to conclude that the ferromagnetic signature does not originate from minor secondary phase, with confidence level of 99.97%.

Nanotechnology is a field of applied science, focused on the design, synthesis, characterization and application of materials and devices at the nanoscale. This is an emerging field which plays a major role in the development of innovative methods to produce new products. Because of its greater role in enhancing the performance of several existing technologies, it is gaining high attention. Properties of materials often change dramatically when size reduces to nanoscale as compared to that of bulk. Material made from nano-size particles that are smaller than 100 nanometers can suddenly become much stronger than those predicted by existing materials-science models.There are two main reasons for which materials property differ at the nanoscale. First, nanomaterials have a relatively larger surface area when compared to their bulk material. Because of this, nanomaterials are chemically more reactive and this will affect their strength or electrical properties. Second, at nano scale quantum effects can begin to dominate which again affects the optical, electrical and magnetic behaviour of materials[1,2,3].