Phase separation induced by oxygen isotope substitution in manganites of the Sm1−x SrxMnO3 system

2004 ◽  
Vol 46 (10) ◽  
pp. 1884-1890 ◽  
Author(s):  
N. A. Babushkina ◽  
E. A. Chistotina ◽  
O. Yu. Gorbenko ◽  
A. R. Kaul ◽  
K. I. Kugel ◽  
...  
Keyword(s):  
Phase Separation ◽  
Oxygen Isotope ◽  
Isotope Substitution

scholarly journals Effect of oxygen isotope substitution and crystal microstructure on magnetic ordering and phase separation in(La1−yPry)0.7Ca0.3MnO3

2007 ◽  
Vol 75 (5) ◽  
Author(s):  
V. Yu. Pomjakushin ◽  
D. V. Sheptyakov ◽  
K. Conder ◽  
E. V. Pomjakushina ◽  
A. M. Balagurov
Keyword(s):  
Phase Separation ◽  
Oxygen Isotope ◽  
Magnetic Ordering ◽  
Isotope Substitution ◽  
Effect Of Oxygen

Effect of oxygen isotope substitution on charge ordering and magnetic and transport properties inPr0.5Ca0.5MnO3doped by chromium and ruthenium

2008 ◽  
Vol 78 (21) ◽  
Author(s):  
N. A. Babushkina ◽  
A. N. Taldenkov ◽  
A. V. Inyushkin ◽  
A. Maignan ◽  
D. I. Khomskii ◽  
...  
Keyword(s):  
Transport Properties ◽  
Oxygen Isotope ◽  
Charge Ordering ◽  
Isotope Substitution ◽  
Effect Of Oxygen

Site-selective oxygen-isotope substitution inYBa2Cu3O7−δ

1991 ◽  
Vol 44 (17) ◽  
pp. 9556-9561 ◽  
Author(s):  
Donald E. Morris ◽  
Andrea G. Markelz ◽  
John Y. T. Wei ◽  
Charles T. Hultgren ◽  
Janice H. Nickel ◽  
...  
Keyword(s):  
Oxygen Isotope ◽  
Isotope Substitution ◽  
Site Selective

Apatite Texture, Composition, and O-Sr-Nd Isotope Signatures Record Magmatic and Hydrothermal Fluid Characteristics at the Black Mountain Porphyry Deposit, Philippines

2021 ◽  
Author(s):  
Ming Jian Cao ◽  
Noreen J. Evans ◽  
Pete Hollings ◽  
David R. Cooke ◽  
Brent I.A. McInnes ◽  
...  
Keyword(s):  
Phase Separation ◽  
High Temperature ◽  
Oxygen Isotope ◽  
Hydrothermal Alteration ◽  
Hydrothermal Fluid ◽  
Isotope Composition ◽  
Hydrothermal Fluids ◽  
Nd Isotope ◽  
O Isotope ◽  
Black Mountain

Abstract The trace elemental and isotopic signatures in apatite can be modified during hydrothermal alteration. This study investigates the suitability of apatite as an indicator of the source, chemistry, and evolution of magma and hydrothermal fluids. In situ textural, elemental, and O-Sr-Nd isotope analyses were performed on apatite in thin sections, from fresh and propylitically altered pre- and synmineralized dioritic porphyries from the Black Mountain porphyry Cu deposit in the Philippines. All studied apatite crystals have similar subhedral to euhedral shapes and are homogeneous in the grayscale in backscattered electron images. In cathodoluminescence images, the apatite in fresh and altered rocks displays yellow to yellow-green and green to brown luminescence, respectively. Apatite in fresh rocks has a higher Cl and Mn content, and lower Fe, Mg, Sr, Pb, and calculated XOH-apatite, compared to apatite in altered rocks. The content of F, rare earth elements (REEs), Y, U, Th, and Zr, and the Sr-Nd isotope signatures of apatite from fresh and altered rocks are similar in all apatite grains (87Sr/86Sr = 0.7034–0.7042 vs. 0.7032–0.7043, εNd(t) = 5.3–8.0 vs. 5.1–8.4). The X-ray maps and elemental and oxygen isotope signatures across individual apatite crystals are typically homogeneous in apatite from both fresh and altered rocks. The distinct luminescence colors, coupled with distinct mobile element compositions (Cl, OH, Mn, Mg, Fe, Sr, Pb), indicate modification of primary magmatic apatite during interaction with hydrothermal fluids. The similarities in Sr isotope ratios (87Sr/86Sr = 0.7032–0.7043) but slight differences in O isotope signatures (δ18O = 6.0 ± 0.3‰ vs. 6.6 ± 0.3‰) in apatite from fresh and altered rocks are consistent with the magma and hydrothermal fluids having the same source and suggest significant phase separation in the hydrothermal fluids given that 18O preferentially fractionates into the residual liquid relative to 16O during phase separation. The similarity of immobile element (REE, Y, U, Th, and Zr) contents in both populations of apatite, consistency of textures and Nd isotope compositions, and absence of obvious dissolution-reprecipitation features all suggest that altered apatite retains some magmatic characteristics. The apatite in fresh rocks has oxygen isotope compositions similar to that of zircons from the same sample (δ18O = 5.9 ± 0.3‰), indicating little to no oxygen isotope fractionation between zircon and apatite and that apatite can be a good proxy for the oxygen isotope composition of the magma. Based on the Cl contents of the magmatic and replacement apatite, and assuming their equilibrium with high-temperature magma fluid and replacement hydrothermal fluid, respectively, the calculated Cl content of the early magmatic fluid and the later replacement fluid can be estimated to be 6.4 to 15.1 wt % and ~0.25 ± 0.03 wt %, respectively. This indicates a depletion of Cl from the early high-temperature fluid to the replacement fluid, consistent with phase separation. This study demonstrates that cathodoluminescence, elemental compositions (such as Cl, Mn, Mg, Fe, Sr, Pb) and Sr-O isotope signatures in apatite can be modified during hydrothermal alteration, whereas other components (REE, Y, U, Th, and Zr) and the Nd isotope composition are preserved. These features can be used to constrain the origin, chemistry, and evolution of the primary magma and ore-forming hydrothermal fluids.

The effect of oxygen isotope substitution on magnetic properties of (La1-yPry)0.7Ca0.3MnO3manganites

1999 ◽  
Vol 11 (30) ◽  
pp. 5865-5873 ◽  
Author(s):  
N A Babushkina ◽  
L M Belova ◽  
A N Taldenkov ◽  
E A Chistotina ◽  
D I Khomskii ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Oxygen Isotope ◽  
Isotope Substitution ◽  
Effect Of Oxygen

Evolution of ( La 1 - y Pr y ) 0.7 Ca 0.3 MnO 3 crystal structure with A-cation size, temperature, and oxygen isotope substitution

2001 ◽  
Vol 19 (2) ◽  
pp. 215-223 ◽  
Author(s):  
A.M. Balagurov ◽  
V.Yu. Pomjakushin ◽  
D.V. Sheptyakov ◽  
V.L. Aksenov ◽  
N.A. Babushkina ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Oxygen Isotope ◽  
Isotope Substitution ◽  
Cation Size

Asymmetric Autocatalysis: Triggered by Chiral Isotopomer Arising from Oxygen Isotope Substitution

2011 ◽  
Vol 123 (35) ◽  
pp. 8281-8283 ◽  
Author(s):  
Tsuneomi Kawasaki ◽  
Yasushi Okano ◽  
Etsuharu Suzuki ◽  
Shizuka Takano ◽  
Shotaro Oji ◽  
...  
Keyword(s):  
Oxygen Isotope ◽  
Isotope Substitution ◽  
Asymmetric Autocatalysis

scholarly journals Effect of Eu doping and partial oxygen isotope substitution on magnetic phase transitions in (Pr1 − y Eu y )0.7Ca0.3CoO3 cobaltites

2014 ◽  
Vol 118 (2) ◽  
pp. 266-278 ◽  
Author(s):  
N. A. Babushkina ◽  
A. N. Taldenkov ◽  
S. V. Streltsov ◽  
A. V. Kalinov ◽  
T. G. Kuzmova ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Oxygen Isotope ◽  
Magnetic Phase ◽  
Magnetic Phase Transitions ◽  
Isotope Substitution ◽  
Partial Oxygen
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