Molecular dynamics of adducts of organotin(IV) and tin(IV) chlorides with NN′-ethylenebis(salicylideneimine) studied by temperature-dependent Mössbauer spectroscopy

1980 ◽  
pp. 1983-1987 ◽  
Author(s):  
Renato Barbieri ◽  
Arturo Silvestri ◽  
Lorenzo Pellerito ◽  
Antonio Gennaro ◽  
Michele Petrera ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Mössbauer Spectroscopy ◽  
Mossbauer Spectroscopy ◽  
Temperature Dependent ◽  
Mößbauer Spectroscopy

Ternary Stannides RE3Ru4Sn13 (RE = La, Ce, Pr, Nd) – Structure, Magnetic Properties, and 119Sn Mössbauer Spectroscopy

2011 ◽  
Vol 66 (7) ◽  
pp. 664-670
Author(s):  
◽  
Christian Schwickert ◽  
Thorsten Langer ◽  
Rainer Pöttgen
Keyword(s):  
Mössbauer Spectroscopy ◽  
Mossbauer Spectroscopy ◽  
Three Dimensional ◽  
Magnetic Ordering ◽  
119Sn Mössbauer Spectroscopy ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Mößbauer Spectroscopy ◽  
Arc Melting ◽  
Different Types

The ternary stannides RE3Ru4Sn13 (RE = La, Ce, Pr, Nd) were obtained by arc-melting of the elements. The polycrystalline samples were characterized by powder X-ray diffraction. The structures of three compounds were refined from single-crystal diffractometer data: Yb3Rh4Sn13 type, Pm3̄n, a = 977.74(3) pm, wR2 = 0.0379, 280 F2 values for La3Ru4Sn13, a = 971.34(9) pm, wR2 = 0.0333, 274 F2 values for Ce3Ru4Sn13, a = 970.68(8) pm, wR2 = 0.0262, 272 F2 values for Nd3Ru4Sn13 with 13 variables per refinement. The structures consist of three-dimensional networks of condensed RuSn6/2 trigonal prisms with the RE (CN 16) and Sn2 (CN 12) atoms in two different types of cavities of the networks. The two crystallographically independent tin sites have been resolved by 119Sn Mössbauer spectroscopy. Temperature-dependent magnetic susceptibility measurements of Ce3Ru4Sn13 gave a reduced magnetic moment of 2.32 μB per Ce atom, indicating intermediate cerium valence. No magnetic ordering was evident down to 3 K.

Polyacrylic acid pore-filled microporous membranes and their use in membrane-mediated synthesis of nanocrystalline ferrihydrite

1998 ◽  
Vol 76 (1) ◽  
pp. 10-17 ◽  
Author(s):  
Françoise M Winnik ◽  
André Morneau ◽  
Alicja M Mika ◽  
Ronald F Childs ◽  
Anna Roig ◽  
...  
Keyword(s):  
Mössbauer Spectroscopy ◽  
Iron Oxide ◽  
Acrylic Acid ◽  
Mossbauer Spectroscopy ◽  
Ferrous Ions ◽  
Temperature Dependent ◽  
Mößbauer Spectroscopy ◽  
Graft Yield ◽  
Water Contents ◽  
Poly Acrylic Acid

A series of cation-exchange membranes were obtained by photoinitiated grafting of acrylic acid onto a polypropylene microporous support having 0.2 µm diameter pores. The poly(acrylic acid) was shown to be contained within the pores of the membrane. The ion-exchange capacities of these "pore-filled" membranes ranged from 65 to 80% of the theoretical values calculated on the basis of their measured graft yields, with water contents ranging from 72 to 77%. The membranes exhibited a chemical valve effect of flux as a function of pH. Treatment of a poly(acrylic acid) grafted membrane with a solution containing ferrous ions resulted in a large uptake of iron (>24% by weight of iron with a membrane containing 152% graft yield of poly(acrylic acid)). Subsequent alkaline (pH 14) oxidation at 70°C with either oxygen or hydrogen peroxide led to the formation of a superparamagnetic nanocrystalline form of ferrihydrite, 5Fe2O3 ·9H2O. The oxide was identified by temperature-dependent Mössbauer spectroscopy recorded from 300 K to 4.2 K. TEM micrographs of sectioned membranes that were treated with H2O2 revealed the presence of two iron oxide morphologies, disk-shaped particles 3-4 nm in diameter and needle-like particles about 4 nm wide and 50 nm long. Only disk-shaped particles were observed in membranes treated with O2. Magnetization measurements indicate that the membranes are superparamagnetic above 50 K with a room temperature magnetization of 3.3 emu g-1 at 20 kOe.Key words: membrane, poly(acrylic acid); iron oxide, magnetic, Mössbauer spectroscopy; magnetization, photografting.

Ferro-and Antiferromagnetic Behaviors of Some Organomatallic and Coordinated Compounds

1992 ◽  
Vol 247 ◽  
Author(s):  
H. H. Wei ◽  
Y. F. Chang
Keyword(s):  
Mössbauer Spectroscopy ◽  
Applied Field ◽  
Mössbauer Spectra ◽  
Mossbauer Spectroscopy ◽  
Magnetic Measurements ◽  
Spontaneous Magnetization ◽  
Temperature Dependent ◽  
Mossbauer Spectra ◽  
Mößbauer Spectroscopy

ABSTRACTSeveral new examples of ferro- and antiferromagnetic organometallic and coordinated compounds have been investigated by means of the temperature-dependent magnetic measurements and Mössbauer spectroscopy. Above 70 K the Cu3 [Fe(CN)6] 2-4H2O compound is ferromagnetic as it obeys the Curie-Weiss experession, χm= C/(T-θ), with θ = 25 K; μeff evalued at 200 K is 4.91 μβ. Below 20 K this compound displays the onset of spontaneous magnetization in zero applied field. Above 10 K the Cu[(bpy>2] 3 [Fe(CN)6] 2.5H2O is also ferromagnetic (θ= 2.5 K). Above 20 K the antiferromagnetic [Fe(C5H4Me)2] + [TCNOJ- (θ= 3.25 K) and [Fe(C5H4Me)2]+[TCNE]- (θ= -3.64 K) obey the Curie-Weiss expression. The e.p.r. and Mössbauer spectra for these compounds have been discussed.

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