Minor Channel Research Articles

Inducing half metallicity with alloying in Heusler Compound CoFeMnSb

First principles studies were performed in order to find out the possibility of inducing half-metallicity in Heusler Compound CoFeMnSb, by means of alloying it with 3d-transition metal elements. Proper alloying element is selected through the calculations of formation energies. These calculations were tested with different concentrations of alloying elements at different atomic sites. Among the selected transition metal elements Sc and Ti are proposed to be excellent alloying elements, particularly at Mn site. By using these alloying elements complete half metallic behaviour is obtained in , , , , and CoFeTiSb alloys. Shifting of Co–Fe d-states towards lower energy region leads to zero density of states at Fermi level for the spin minority channel. Alloying effects on the electronic structure and magnetization are discussed in details. Thermodynamical stability of these new alloys is a major part of this study. The Curie temperatures of and were found to be 324.5 K and 682 K; respectively, showing good candidature for spintronics applications. For understanding the bonding nature of the constituent atom of CoFeMnSb, crystal orbital Hamiltonian populations have been analysed.

A XMS-CASPT2 non-adiabatic dynamics study on pyrrole

The photoinduced dynamics of pyrrole is revisited employing the independent trajectory surface hopping methodology based on extended multi-state second order perturbation theory (XMS-CASPT2). Excitation at 200 nm into a high density of states region gives rise to ultrafast deactivation via internal conversion. The primary dissociation channel was found to be NH hydrogen abstraction, resulting in pyrrolyl radical formation. The associated time constant for hydrogen dissociation was determined to be 64 ± 13 fs, in good agreement with the experimental value of 52 ± 12 fs (Roberts et al., 2013). A total kinetic energy spectrum was also computed, that is in qualitative agreement with experiment. Radiationless decay via the ring-puckering crossing seam was identified as a minor deactivation channel.

The tectono-sedimentary evolution of a major seismogenic zone with low slip rate activity: A geochronological and sedimentological investigation of the Dobrá Voda Depression (Western Carpathians)

Seismically active fault zones receive a great deal of attention due to their potential for quantification of seismic hazards. Zones with low slip rates pose a challenge, however, since their poor topographic expression is related to difficulties in the quantification of fault movement. This study focuses on the Dobrá Voda Depression, an area with the highest level of seismic activity in the Western Carpathians. The Quaternary tectono-sedimentary evolution of the small intramontane basin was investigated with the use of facies analysis of cores, dated with the use of cosmogenic nuclide depth profiles (10Be, 26Al and 36Cl), together with 26Al/10Be burial dating and radiocarbon dating. A set of archived boreholes and geoelectric survey data was used for the correlation of results with those from new boreholes across the depression. Four facies associations were distinguished: (FA1) Colluvial deposits that comprise subaerial debris flows and mudflows; (FA2) Fluvial deposits with high sediment supply: accommodation ratio, composed mostly of sandy-gravelly channel fill facies; (FA3) Fluvial deposits with low sediment supply: accommodation ratio, consisting mostly of floodplain muds, overbank heterolithic facies and minor sandy-gravelly channel fills; and (FA4) Swamp deposits, which are mostly made up of peat. Geochronological results suggest that the studied part of FA3 was deposited before 1.0 Ma due to a rise in the base level following a major incision event. Overbank-dominated deposits of FA3 covered an incision surface, resulted in a difference of ca. 65 m of elevation of these strata, which represents the minimal thickness of FA3. The second phase of incision was related to reactivation of Miocene normal faults resulting in further topographic differentiation. The initiation of fault activity is recorded by the deposition of colluvial FA1 before ca. 250 ka. FA2 accumulated between ca. 160 and 100 ka, mostly at the toes of slopes bounding the fault scarps on the basin margins. The last documented phase of evolution represents an increase of accommodation, which was connected to the deposition of Holocene peat in swamps as well as floodplain muds of FA4 above FA2. The observed settings imply that variation between incision and accumulation in a scale of hundreds of thousands of years is characteristic for low relief tectonically active zones. The presented research demonstrates the significance of sedimentological analysis for reconstruction of tectonic evolution in areas with low slip rate activity.

Sedimentological characteristics and controlling factors on fluvial styles of the Guantao Formation, Kongdian Oilfield, China

The Kongdian Oilfield is located in eastern China. More than 30 years have passed since the oil field was discovered in 1979. The majority of the oil is produced from reservoirs of the Guantao Formation (Miocene). A detailed description and interpretation of core, well-logging and 3-D seismic stratal slices data was carried out to analyze sedimentological characteristics of the Guantao Formation and two fluvial styles have been identified encompassing braided channel and meandering channel. Seven main facies associations were defined: (i) upward-fining channel, (ii) braided channel with mid-channel bar, (iii) meandering channel with point bar, (iv) levee, (v) floodplain, (vi) minor channel, (vii) swamp. Vertical changes in fluvial styles of the Guantao Formation were recognized by variations in preserved thickness, channels stacking pattern, regional paleoflow directions, and channel/floodplain ratios. The fluvial succession is 50–70 m thick in the lower Guantao Formation, composed of braided channels and high channel/floodplain ratio. The alluvial succession is 60 m in thickness in the upper Guantao Formation, the dominant fluvial styles change to meandering channels and channel/floodplain ratio reduces. The main factor that may have affected the fluvial style is the base-level changes. With the rise of the base level the fluvial style is believed to have changed from braided channels to meandering channels.

Unveiling the photophysics of thiourea from CASPT2/CASSCF potential energy surfaces and singlet/triplet excited state molecular dynamics simulations

This work describes the decay mechanism of photoexcited thiourea, both in gas phase and in solution, from the information inferred from the topography of the excited and ground state potential energy surfaces and mixed singlet/triplet quantum classical molecular dynamics simulations. Our gas phase results reveal T1/S0 intersystem crossing as the dominant (49%) intrinsic decay channel to the ground state, which reaches a population of 0.28 at the final time of our simulations (10 ps). Population of the T1, would occur after internal conversion to the S1 from the spectroscopic S2 electronic state, followed by S1 → T2 intersystem crossing and T2 → T1 internal conversion processes. Minor decay channels occurring exclusively along the singlet manifold, i.e. S2 → S0 (33%) and S1 → S0 (18%), were also observed to play a role in the relaxation of photoexcited thiourea in the gas phase. The explicit incorporation of water-thiourea interactions in our simulations was found to provoke a very significant delay in the decay to the ground state of the system, with no transitions to the S0 being registered during the first 10 ps of our simulations. Intermolecular vibrational energy redistribution and explicit hydrogen bond interactions established between water molecules and the NH2 group of thiourea were found to structurally or energetically hamper the access to the intersystem crossing or internal conversion funnels with the S0.

Temperature- and Mn2+ Concentration-Dependent Emission Properties of Mn2+-Doped ZnSe Nanocrystals.

Mn2+-doped ZnSe nanocrystals (Mn:ZnSe d-dots) with high optical quality-high dopant emission quantum yield with monoexponential dopant-emission decay dynamics-enable systematic and quantitative studies of temperature- and Mn2+ concentration-dependent optical properties of the dopant emission, especially its relationship with magnetic coupling. While temperature-dependent steady-state and transient dopant emission of d-dots with dilute Mn2+ concentrations originated from isolated Mn2+ ions, and can be quantitatively treated as a result of exciton-phonon coupling of isolated paramagnetic emission centers. Dopant emission of d-dots with high Mn2+ concentrations (up to 50% of Zn2+ ions being replaced by Mn2+ ions in the core nanocrystals) are found solely related to magnetically coupled Mn2+ emission. Magnetic coupling effects on steady-state dopant emission of d-dots with high Mn2+ concentrations are much stronger than those observed for doped bulk semiconductors, which is found to follow a strong and universe shell-thickness dependence for the epitaxial ZnSe and/or ZnS shells of the d-dots. By exciting the magnetically coupled Mn2+ ions directly, dopant-emission of d-dots with high Mn2+ concentrations exhibit monoexponential decay dynamics. In addition to this emission channel, a minor channel with slightly longer decay lifetime appears when the host nanocrystals with high Mn2+ concentrations are excited, which is barely visible at room temperature and increases its fraction by decreasing temperature.

Photochemistry of 2-butenedial and 4-oxo-2-pentenal under atmospheric boundary layer conditions.

Unsaturated 1,4-dicarbonyl compounds, such as 2-butenedial and 4-oxo-2-pentenal are produced in the atmospheric boundary layer from the oxidation of aromatic compounds and furans. These species are expected to undergo rapid photochemical processing, affecting atmospheric composition. In this study, the photochemistry of (E)-2-butenedial and both E and Z isomers of 4-oxo-2-pentenal was investigated under natural sunlight conditions at the large outdoor atmospheric simulation chamber EUPHORE. Photochemical loss rates, relative to j(NO2), are determined to be j((E)-2-butenedial)/j(NO2) = 0.14 (±0.02), j((E)-4-oxo-2-pentenal)/j(NO2) = 0.18 (±0.01), and j((Z)-4-oxo-2-pentenal)/j(NO2) = 0.20 (±0.03). The major products detected for both species are a furanone (30-42%) and, for (E)-2-butenedial, maleic anhydride (2,5-furandione) (12-14%). The mechanism appears to proceed predominantly via photoisomerization to a ketene-enol species following γ-H abstraction. The lifetimes of the ketene-enol species in the dark from 2-butenedial and 4-oxo-2-pentenal are determined to be 465 s and 235 s, respectively. The ketene-enol can undergo ring closure to yield the corresponding furanone, or further unimolecular rearrangement which can subsequently form maleic anhydride. A minor channel (10-15%) also appears to form CO directly. This is presumed to be via a molecular elimination route of an initial biradical intermediate formed in photolysis, with an unsaturated carbonyl (detected here but not quantified) as co-product. α-Dicarbonyl and radical yields are very low, which has implications for ozone production from the photo-oxidation of unsaturated 1,4-dicarbonyls in the boundary layer. Photochemical removal is determined to be the major loss process for these species in the boundary layer with lifetimes of the order of 10-15 minutes, compared to >3 hours for reaction with OH.

The conditions for occurrence of critical flow regime of water in the open stream

For the solution of engineering problems require increasingly accurate estimates of the hydraulic characteristics of the water streams. To date, it is impossible to consider sufficiently complete theoretical and experimental justification of the main provisions of the theory of turbulence, hydraulic resistance, channel processes. The composition of tasks related to flows in wide channels, turbulence problems are of scientific and practical interest. Various interpretations of the determination of the critical Froude number in wide open water flows based on observations and theoretical transformations are considered. The conditions for the emergence of a critical regime of water flow in an open wide channel are analyzed in order to estimate the critical Froude number and critical depth. Estimates of the critical Froude number for laboratory and field conditions are given. The estimations allow us to consider the proposed approach acceptable for determining the conditions of occurrence of the critical flow regime. The General, physical interpretation of conditions of occurrence of the critical regime of water flow on the basis of phenomenological approach is specified. The results take into account the values of the components of the total specific energy of the section. This shows the estimated calculation. The results obtained theoretically make it possible to compare the above interpretations and determine their applicability, and the results of the analysis can be useful for the estimated calculations of flows in channels and river flows in rigid, undeformable boundaries and with minor channel deformations.

Electronic structure, magnetism properties and optical absorption of organometal halide perovskite CH3NH3XI3 (X = Fe, Mn)

The electronic structure, magnetism properties and optical absorption of organometal halide perovskite CH3NH3XI3 (X = Fe, Mn) are studied using the first principles calculations by the generalized gradient approximation (GGA) and the GGA + U method, respectively. The magnetic ground states of CH3NH3MnI3 and CH3NH3FeI3 are both the G-type antiferromagnetic (AFM) order. With the introduction of on-site Coulomb interactions U, CH3NH3FeI3 shows the semiconducting phase from original metallic state predicted by the GGA method. The band gap value of CH3NH3MnI3 with the G-AFM state is 1.68 eV, while the band gap in the spin majority channel is 0.694 eV and the band gap in the spin minority channel is 2.147 eV when system is in FM state. For CH3NH3FeI3 system, the band gap is 0.957 eV when system is in G-AFM state, while the band gap in the spin majority channel is 0.602 eV and the band gap in the spin minority channel is 1.215 eV when system is in FM state, which shows that photo-excited electrons of CH3NH3MnI3 and CH3NH3FeI3 with FM state will rapidly melt the local magnetic order. Furthermore, the optical properties of CH3NH3MnI3 and CH3NH3FeI3 are calculated. CH3NH3MnI3 with the FM state shows strong infrared light absorption. CH3NH3FeI3 with FM state have stronger infrared absorption than that in G-AFM state.

Reaction of Perfluorooctanoic Acid with Criegee Intermediates and Implications for the Atmospheric Fate of Perfluorocarboxylic Acids.

The reaction of perfluorooctanoic acid with the smallest carbonyl oxide Criegee intermediate, CH2OO, has been measured and is very rapid, with a rate coefficient of (4.9 ± 0.8) × 10-10 cm3 s-1, similar to that for reactions of Criegee intermediates with other organic acids. Evidence is shown for the formation of hydroperoxymethyl perfluorooctanoate as a product. With such a large rate coefficient, reaction with Criegee intermediates can be a substantial contributor to atmospheric removal of perfluorocarboxylic acids. However, the atmospheric fates of the ester product largely regenerate the initial acid reactant. Wet deposition regenerates the perfluorocarboxylic acid via condensed-phase hydrolysis. Gas-phase reaction with OH is expected principally to result in formation of the acid anhydride, which also hydrolyzes to regenerate the acid, although a minor channel could lead to destruction of the perfluorinated backbone.

Design of a polar half-metallic ferromagnet with accessible and enhanced electric polarization

We design a compound belonging to a class of materials designated as polar half-metallic ferromagnets, where a 100% spin polarization coexists with polar distortions that globally lift inversion symmetry. Using electronic structure calculations, we predict that the ultrashort period ${({\mathrm{LaNiO}}_{3})}_{1}/{({\mathrm{YCrO}}_{3})}_{1}$ superlattice belongs to this materials class, exhibiting an integer magnetic moment of $4\phantom{\rule{3.33333pt}{0ex}}{\ensuremath{\mu}}_{B}$. The minority channel electric polarization, as computed using Berry phase theory, is as high as $\ensuremath{\sim}13.0\phantom{\rule{0.16em}{0ex}}\ensuremath{\mu}\mathrm{C}\phantom{\rule{0.16em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}2}$, and we discuss experimental strategies to access the polarization. We propose that polar ferromagnetic half-metals exhibit multiferroism and can be exploited to realize nonreciprocal effects and directional anisotropy owing to the absence of both space-inversion and time-reversal symmetries.

Photoinduced Heterocyclic Ring Opening of Furfural: Distinct Open-Chain Product Identification by Ultrafast X-ray Transient Absorption Spectroscopy.

The ultraviolet-induced photochemistry of five-membered heterocyclic rings often involves ring opening as a prominent excited-state relaxation pathway. The identification of this particular photoinduced mechanism, however, presents a challenge for many experimental methods. We show that femtosecond X-ray transient absorption spectroscopy at the carbon K-edge (∼284 eV) provides core-to-valence spectral fingerprints that enable the unambiguous identification of ring-opened isomers of organic heterocycles. The unique differences in the electronic structure between a carbon atom bonded to the oxygen in the ring versus a carbon atom set free of the oxygen in the ring-opened product are readily apparent in the X-ray spectra. Ultrafast ring opening via C-O bond fission occurs within ∼350 fs in 266-nm photoexcited furfural, as evidenced by fingerprint core (carbon 1s) electronic transitions into a nonbonding orbital of the open-chain carbene intermediate at 283.3 eV. The lack of recovery of the 1sπ* ground-state depletion in furfural at 286.4 eV indicates that internal conversion to the ground state is a minor channel. These experimental results, augmented by recent advances in the generation of isolated attosecond pulses at the carbon K-edge, will pave the way for probing ring-opened conical intersection dynamics in the future.

Comparison of internal conversion dynamics of azo and azoxy energetic moieties through the (S1/S0)CI conical Intersection: An ab initio multiple spawning study

We have explored the nonadiabatic chemical dynamics of trans-azomethane (AM) and azoxymethane (AOM) using ab initio multiple spawning (AIMS) simulation and CASSCF theory. A trans-to-cis isomerization around the N = N bond and a pyramidalization of the N(O)N moiety are predicted to be involved in the internal conversion process of AM and AOM molecules, respectively. AIMS-based simulation at the CASSCF(6,4)/6-31G(d) level of theory reveals that electronically excited AM and AOM molecules undergo extremely fast (approximately in 125 fs for AM and 64 fs for AOM) relaxation to the ground state via the (S1/S0)CI conical intersection. In addition, AIMS simulation at the CASSCF(10,8)/6-31G(d) level of theory reveals that AM molecules exhibit two relaxation pathways: major (comprising 75%) channel involves an isomerization process and minor (comprising 25%) channel features the C-N bond dissociation.

Photochemistry and spectroscopy of small hydrated magnesium clusters Mg+(H2O)n, n = 1-5.

Hydrated singly charged magnesium ions Mg+(H2O)n, n ≤ 5, in the gas phase are ideal model systems to study photochemical hydrogen evolution since atomic hydrogen is formed over a wide range of wavelengths, with a strong cluster size dependence. Mass selected clusters are stored in the cell of an Fourier transform ion cyclotron resonance mass spectrometer at a temperature of 130 K for several seconds, which allows thermal equilibration via blackbody radiation. Tunable laser light is used for photodissociation. Strong transitions to D1–3 states (correlating with the 3s-3px,y,z transitions of Mg+) are observed for all cluster sizes, as well as a second absorption band at 4–5 eV for n = 3-5. Due to the lifted degeneracy of the 3px,y,z energy levels of Mg+, the absorptions are broad and red shifted with increasing coordination number of the Mg+ center, from 4.5 eV for n = 1 to 1.8 eV for n = 5. In all cases, H atom formation is the dominant photochemical reaction channel. Quantum chemical calculations using the full range of methods for excited state calculations reproduce the experimental spectra and explain all observed features. In particular, they show that H atom formation occurs in excited states, where the potential energy surface becomes repulsive along the O⋅⋅⋅H coordinate at relatively small distances. The loss of H2O, although thermochemically favorable, is a minor channel because, at least for the clusters n = 1-3, the conical intersection through which the system could relax to the electronic ground state is too high in energy. In some absorption bands, sequential absorption of multiple photons is required for photodissociation. For n = 1, these multiphoton spectra can be modeled on the basis of quantum chemical calculations.

The photoinduced isomerization mechanism of the 2-(1-(methylimino)methyl)-6-chlorophenol (SMAC): Nonadiabatic surface hopping dynamics simulations.

The photophysical properties of the Schiff base family are crucial for their applications such as molecular switches and molecular memories. However, it was found that the photophysical behavior is not uniform for all Schiff base molecules, which shows a significant substituent dependent property. In this article, we studied the photoisomerization mechanism of one Schiff base chlorosubstituted derivative 2-(1-(methylimino)methyl)-6-chlorophenol by employing geometrical optimization, energy profiles scanning, and on-the-fly dynamical simulations. Three types of minimum energy conical intersections were located on the S1/S0 crossing seam, with two characterized by twisting motion of the C=N bond and one featured with the excited state intramolecular proton transfer process and then twisting motion around the C=C bond [excited-state intramolecular proton transfer process (ESIPT)-then-twisting]. By a combination of the dynamics simulation results with the energy profiles scanned along with the ESIPT coordinate, it was found that the photophysical property of the targeted molecule is different from that of most Schiff base members, which prefer to decay by a twisting motion around the C=N bridge bond rather than the ESIPT-then-twisting channel. The minor ESIPT channel is probably governed by a tunneling mechanism. The proposed deactivation mechanism can provide a reasonable explanation for the observations in the experiment and would provide fundamental indications for further design of new and efficient photochromic products.

Refined dependences of power-law form for calculation of hydraulic resistance and velocity distribution

To solve the engineering problems of hydraulic engineering, water supply and sanitation, prevent emergency situations at hydraulic structures, regulate channel processes, efficient ecological monitoring of water bodies, and develop measures that exclude crisis ecological situations, more and more accurate estimates are required for the hydraulic characteristics of water flows. Inaccurate assumptions and approximate methods of integration can lead to significant errors that significantly affect the results of predicting flooding of riverine areas; this requires further refinement of the calculation methods. Until now, theoretical and experimental substantiations of the basic propositions of the theory of turbulence, hydraulic resistances, channel processes cannot be considered sufficiently complete. The compositions of problems associated with flows in wide channels, problems of turbulence, ax symmetric flows in smooth and rough pipes, are of scientific and practical interest. The article investigates the dependencies for the calculation of kinematic and dynamic flow characteristics in deformed and undeformable boundaries. New formulas are given for a refined description of the distribution of flow velocities and hydraulic resistance of turbulent flows in pipes and channels. Based on the known fundamental research, the calculation-theoretical methods are refined. The results obtained for flows in non-deformable channels can be useful for estimating not only flow in pipes, but also river flows in hard, undeformable boundaries and with minor channel deformations (in channels and rivers). For the first time, the analysis made it possible to obtain power-law approximations of the resistance laws for smooth and rough tubes and to establish the actual relationship between the exponents in the velocity profile and the law of resistance.

Magnetic field control of charge excitations in CoFe2O4.

We combine magnetic circular dichroism and photoconductivity with prior optical absorption and first principles calculations to unravel spin-charge interactions in the high Curie temperature magnet CoFe2O4. In addition to revising the bandgap hierarchy, we reveal a broad set of charge transfer excitations in the spin down channel which are sensitive to the metamagnetic transition involving the spin state on Co centers. We also show photoconductivity that depends on an applied magnetic field. These findings open the door for the creation and control of spin-polarized electronic excitations from the minority channel charge transfer in spinel ferrites and other earth-abundant materials.

Reversible Photoisomerization of the Isolated Green Fluorescent Protein Chromophore.

Fluorescent proteins have revolutionized the visualization of biological processes, prompting efforts to understand and control their intrinsic photophysics. Here we investigate the photoisomerization of deprotonated p-hydroxybenzylidene-2,3-dimethylimidazolinone anion (HBDI-), the chromophore in green fluorescent protein and in Dronpa protein, where it plays a role in switching between fluorescent and nonfluorescent states. In the present work, isolated HBDI- molecules are switched between the Z and E forms in the gas phase in a tandem ion mobility mass spectrometer outfitted for selecting the initial and final isomers. Excitation of the S1 ← S0 transition provokes both Z → E and E → Z photoisomerization, with a maximum response for both processes at 480 nm. Photodetachment is a minor channel at low light intensity. At higher light intensities, absorption of several photons in the drift region drives photofragmentation, through channels involving CH3 loss and concerted CO and CH3CN loss, although isomerization remains the dominant process.

Elemental concentration and organic petrology of unique liptinite-rich humic coal, canneloid shale, and cannel coal of Devonian age from Arctic Canada

Seventeen coal and carbonaceous shale samples taken from eight stratigraphic sections of the Devonian Hecla Bay and Weatherall formations in Arctic Canada, were examined using reflected light microscopy, instrumental neutron activation analysis (INAA), and inductively coupled plasma emission spectroscopy (ICPES). Samples consist of humic coal with 62–79 vol% vitrinite, liptinite-rich humic coal with 42 vol% liptinite, and cannel coal with 52–81 vol% sporinite content. Carbonaceous shale has 46–73 vol% mineral matter and canneloid shale has 30–42 vol% mineral matter as well as 22–38 vol% sporinite content. Most were deposited in areas characterized by minor channel cut-and-abandonment and lake and bay infills peripheral to distributary complexes. A fresh water environment is indicated by Boron (18–71 ppm), low inertinite (0–7.8 wt%), and high sporinite content (30–81 vol%). The ratio of Na/K versus liptinite content shows that coals and associated sediments from the Hecla Bay Formation experienced a more rapid rate of sedimentation than the carbonaceous shales from the Weatherall Formation. The highest total REEs and LREE (La-Gd) was in the liptinite-rich humic coal, followed by humic coal and carbonaceous shale. The concentration of REEs and LREEs in the cannel coals is half of that measured in the liptinite-rich humic coal. The PAAS normalized for oil shales follows two different patterns: 1) the liptinite-rich coal samples display a sharp increase from Nd to Ho, then maintain a similar pattern up to Lu; and 2) samples of other lithologies increase from Nd to Dy, and then maintain a flat trend up to Lu. Hierarchical cluster analysis shows that canneloid and liptinite-rich coal exhibit the greatest similarity with each other whereas humic coal and liptinite-rich coal show the greatest dissimilarity with carbonaceous shale.

Magnetic properties of chromium-doped Ni80Fe20 thin films

This paper investigates the properties of thin films of chromium-doped Ni80Fe20 (Permalloy) that could potentially be useful in future low-power magnetic memory technologies. The addition of chromium reduces the saturation magnetization, Ms, which is useful for low-energy switching, but does not significantly degrade the excellent switching properties of the host material even down to 10 K, the lowest temperature measured, in films as thin as 2.5 nm. As an example, an alloy film composed of 15% chromium and 85% Ni80Fe20 has an Ms just over half that of pure Ni80Fe20, with a coercivity Hc less than 4 Oe, an anisotropy field Hk less than 1 Oe, and an easy-axis remanent squareness Mr/Ms of 0.9 (where Mr is the remanent magnetization). Magnetodynamical measurements using a pulsed inductive microwave magnetometer showed that the average Landau Lifshitz damping λ was relatively constant with changing Cr content, but increased significantly for thinner films (λ ≈150 MHz for 11 nm, λ ≈250 MHz for 2.5 nm), and at low bias fields likely due to increased magnetic dispersion. Density functional theory calculations show that chromium reduces Ms by entering the lattice antiferromagnetically; it also increases scattering in the majority spin channel, while adding almost insignificant scattering to the minority channel.