The crystal structure of boracite

Ito, Takao; Morimoto, Nobuo; Sadanaga, Ryôichi

doi:10.1107/s0365110x51001033

Cited by 116 publications

(46 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…So far the structures have been determined only for the high and the low temperature phases of the natural Mg-Clboracite, the result being the space groups Td_ and C~v , respectively have shown that this transition is not of the ferro-electric type. It will be shown 7 that the two groups Td_ and C~v cannot correspond to the type of transformation described in reference (2). Contrary to what is stated there, c;v is not a subgroup of Tct.…”

contrasting

confidence: 39%

Magnetic susceptibilities of some 3d transition metal boracites

Schmid

Rieder

Ascher

1965

Solid State Communications

View full text Add to dashboard Cite

Effective magneton nos. and Curie-Weiss temps. of 11 3d-metal boracites were detd. from susceptibility vs. temp. measurements. All boracites investigated display neg. Curie-Weiss temps. Cr-I and Ni-I boracites become antiferromagnetic at about 90° and 120°K., resp. Ni-I boracite shows an anomalous peak of susceptibility at about 60°K. which coincides with the temp. of the simultaneous onset of ferro-electricity and weak ferromagnetism

show abstract

contrasting

confidence: 39%

Magnetic susceptibilities of some 3d transition metal boracites

Schmid

Rieder

Ascher

1965

Solid State Communications

View full text Add to dashboard Cite

show abstract

“…In the mineral boracite Mg3B7O13Cl [2,22], magnesium Mg 2+ ions can be replaced by bivalent 3d-magnetic ions resulting in numerous materials with magnetoelectric and multiferroic…”

mentioning

confidence: 99%

Lattice dynamics and a magnetic-structural phase transition in the nickel orthoborateNi3(BO3)2
Pisarev
¹
,
Prosnikov
²
,
Davydov
³

et al. 2016
Phys. Rev. B
18
1
10
0
View full text Add to dashboard Cite

Nickel orthoborate Ni3(BO3)2 having a complex orthorhombic structure Pnnm (#58, Z=2) of the kotoite type is known for quite a long time as an antiferromagnetic material below We performed the symmetry analysis of the phonon modes at the center of the Brillouin zone.The structural parameters and phonon modes were calculated using Dmol3 program. We report and analyze results of infrared and Raman studies of phonon spectra measured in all required polarizations. Most of the even and odd phonons predicted on the basis of the symmetry analysis and theoretical calculations were reliably identified in the measured spectra. A clear evidence of the spin-phonon interaction was found for some particular phonons below TN. Unexpected emergence of several very narrow and weak phonon lines was observed in the infrared absorption spectra exactly at the magnetic ordering temperature TN. Moreover, anomalous behavior was found for some Raman phonons. Emergence of new phonon modes in the infrared and Raman spectra exactly at TN proves existence of a magnetostructural phase transition of a new type in Ni3(BO3)2. A possible nature of this transition is discussed.

show abstract

“…Ther mal stud ies of these min er als in di cated re vers ible phase tran si tions tak ing place close to the tem per a tures in di cated by other au thors (Ito et al, 1951;Sueno et al, 1973;Schmid and Tippmann, 1978;Car penter, 1996, 1997).…”

Section: Discussionmentioning

confidence: 54%

Phase transitions in the borate minerals from the Kłodawa Salt Dome (Central Poland) as indicators of temperature processes in salt diapirs

Wachowiak

Toboła

2014

View full text Add to dashboard Cite

Wachowiak, J., Tobo³a, T., 2014. Phase tran si tions in the bo rate min er als from the K³odawa salt dome (cen tral Po land) as indi ca tors of tem per a ture pro cesses in salt diapirs. Geo log i cal Quar terly, 58 (3): 543-554, doi: 10.7306/gq.1170The diapiric struc tures of the Pol ish Low lands are tec toni cally deeply seated down to the autochthonous Zechstein strata at a depth of ca. 6 km. In the pro cess of deep burial and halokinetic diapirism, the salt rocks were sub jected to diagenetic and meta mor phic trans for ma tions, with the tem per a ture be ing an es sen tial fac tor. Con sid er ing the ther mal gra di ent, a tem per ature of up to ca. 200°C can be achieved in the salt dome within a depth range from sev eral hun dred metres to 6 km, which may lead to trans for ma tions of the ma jor ity of salt min er als. Phase tran si tions of two bo rate min er als -boracite and congolite from the K³odawa salt dome -pro vide ev i dence for higher tem per a tures in the salt dome rocks. The authigenic euhedral crys tals of those bo rate min er als dis play their ex ter nal habitus in am bi ent tem per a ture in the form of reg u lar sym me try (F43c -pseudo-reg u lar poly he drons), whereas their in ter nal struc ture is lower: orthorhombic (Pca2 1 ) for boracite and rhombohedral (R3 C ) for congolite. The heat ing and cool ing of boracite and congolite crys tals show re vers ible phase tran si tion. At a tem per a ture of ca. 270°C, boracite crys tals change their sym me try: orthorhombic « cu bic. In the case of congolite three revers ible phase tran si tions within a tem per a ture range of 50-339°C can be ob served: rhombohedral « monoclinic « orthorhombic « cu bic sym me try. Those phase tran si tions, con firmed ex per i men tally in our study, clearly doc u ment at least lo cal oc cur rences of tem per a tures ex ceed ing 339°C in the K³odawa salt dome.

show abstract

The crystal structure of boracite

Cited by 116 publications

References 1 publication

Magnetic susceptibilities of some 3d transition metal boracites

Magnetic susceptibilities of some 3d transition metal boracites

Lattice dynamics and a magnetic-structural phase transition in the nickel orthoborateNi3(BO3)2
Pisarev
¹
,
Prosnikov
²
,
Davydov
³

et al. 2016
Phys. Rev. B
18
1
10
0
View full text Add to dashboard Cite

Phase transitions in the borate minerals from the Kłodawa Salt Dome (Central Poland) as indicators of temperature processes in salt diapirs

Contact Info

Product

Resources

About

The crystal structure of boracite

Cited by 116 publications

References 1 publication

Magnetic susceptibilities of some 3d transition metal boracites

Magnetic susceptibilities of some 3d transition metal boracites

Lattice dynamics and a magnetic-structural phase transition in the nickel orthoborateNi3(BO3)2Pisarev1, Prosnikov2, Davydov3 et al. 2016Phys. Rev. B181100View full textAdd to dashboardCite

Phase transitions in the borate minerals from the Kłodawa Salt Dome (Central Poland) as indicators of temperature processes in salt diapirs

Contact Info

Product

Resources

About

Lattice dynamics and a magnetic-structural phase transition in the nickel orthoborateNi3(BO3)2
Pisarev
¹
,
Prosnikov
²
,
Davydov
³

et al. 2016
Phys. Rev. B
18
1
10
0
View full text Add to dashboard Cite