data_Sr2CrO3FeAs

#####################################
# 1. SUBMISSION DETAILS AND AUTHORS #
#####################################

_publ_contact_author
;
        Prof. Dirk Johrendt
        Department Chemie und Biochemie
        Ludwig-Maximilians-Universität München
        Butenandtstrasse 5 - 13 (D)
        D 81377 München
        Germany
;
_publ_contact_author_phone        '+49 89 2180 77430'
_publ_contact_author_fax          '+49 89 2180 77431'
_publ_contact_author_email        'Dirk.Johrendt@cup.uni-muenchen.de'
_publ_requested_journal           'Z. Anorg. Allg. Chem.'
_publ_section_title
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       The layered iron arsenide oxides Sr2CrO3FeAs and Ba2ScO3FeAs.
;

loop_
 _publ_author_name
Tegel, Marcus
Hummel, Franziska
Lackner, Sebastian
Schellenberg, Inga
Poettgen, Rainer
Johrendt, Dirk

 _publ_author_address
;       
        Department Chemie und Biochemie
        Ludwig - Maximilians - Universität München
        Butenandtstrasse 5 - 13 (D)
        D 81377 München
        Germany
;

_publ_section_abstract
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Polycrystalline samples of the layered iron arsenides Sr2CrO3FeAs and
Ba2ScO3FeAs were synthesized by high temperature solid state reactions and their
crystal structures determined by the X-ray powder diffraction. Their structures
are tetragonal (P4/nmm; Sr2CrO3FeAs: a = 391.12(1) pm, c = 1579.05(3) pm;
Ba2ScO3FeAs: a = 412.66(5) pm, c = 1680.0(2) pm, Z = 2) and isotypic to
Sr2ScO3CuS. Iron arsenide layers are sandwiched between perowskite-like oxide
blocks and separated by \~1600 pm, which is much larger compared to the 1111
iron arsenide superconductors. The bond length and angles within the FeAs layers
are adapted to the space requirements of the oxide blocks. Measurements of the
magnetic susceptibility and electrical resistivity show no hint for a SDW-like
anomaly in both compounds. Sr2CrO3FeAs shows Curie-Weiss paramagnetism above
160 K with an effective magnetic moment of 3.83(3) muB in good agreement with
the theoretical value of 3.87 muB for Cr3+. Antiferromagnetic ordering was
detected below TN \~ 31 K. 57Fe Moessbauer spectra of Sr2CrO3FeAs show a single
signal that broadens below the magnetic ordering temperature due to a small
transferred hyperfine field induced by the magnetic ordering of the chromium
atoms. 57Fe-Moessbauer spectra of Ba2ScO3FeAs show single signals at 298, 77,
and 4.2 K which are only subject to weak quadrupole splitting.
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_publ_section_comment 
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?
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_publ_section_references 
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?
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###################
# 2. EXPERIMENTAL #
###################

_publ_section_exptl_prep
; 
A powder pattern was recorded on a STOE STADI P Debye-Scherrer X-Ray
diffractometer (Cu-Kalpha1 radiation, Ge-111 monochromator, transmission
geometry).  
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_diffrn_measurement_device_type        'STOE STADI P'
_diffrn_radiation_probe                x-ray
_diffrn_radiation_polarisn_ratio       ?
_diffrn_radiation_wavelength           1.54056
_diffrn_radiation_type                 'Cu K\a~1~'
_diffrn_radiation_monochromator        'Ge-111'
_geom_special_details                  transmission
_cell_measurement_temperature          297(2)
_exptl_special_details
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 ?
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##########################################
# 3. OVERALL SOLUTION/REFINEMENT DETAILS #
##########################################

_refine_special_details
; 
A Rietveld refinement was performed with the TOPAS package using the fundamental
parameters approach as reflection profiles (convolution of appropriate source
emission profiles with axial instrument contributions as well as crystallite
microstructure effects). In order to describe small peak half width and shape
anisotropy effects, the approach of Le Bail and Jouanneaux was implemented into
the TOPAS program and the according parameters were allowed to refine freely.
Preferred orientation of the crystallites was described with a spherical
harmonics function of 4th order. For details see original publication.
;

_computing_molecular_graphics         'CrystalMaker 8.1.8'
_computing_publication_material       'TOPAS ACADEMIC 4.1'
_audit_creation_method		          'TOPAS ACADEMIC 4.1 + PLATON'
_pd_calc_method                       'Rietveld Refinement'
_computing_structure_solution         none
_computing_structure_refinement       'TOPAS ACADEMIC 4.1'

_refine_ls_shift/su_mean               0.00
_refine_ls_shift/su_max                0.00
_refine_ls_matrix_type                 full
_refine_ls_number_parameters           86
_refine_ls_number_constraints          0
_refine_ls_number_restraints           0
_refine_ls_goodness_of_fit_all         0.969
_pd_proc_ls_prof_R_factor              0.01448
_pd_proc_ls_prof_wR_factor             0.01827
_pd_proc_ls_prof_R_expected            0.01886
_refine_ls_R_Fsqd_factor               0.00177


# if regions of the data are excluded, the reason(s) are supplied here:
_pd_proc_info_excluded_regions
;
 ?
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#####################
# 4. SAMPLE DETAILS #
#####################

_pd_char_colour                   black
_pd_char_particle_morphology      platelet

_chemical_name_systematic
; 
 Strontium chromiom iron arsenide oxide 
;
_chemical_name_common             'Strontium chromiom iron arsenide oxide' 
_chemical_formula_moiety          'As Fe, Cr O3, 2(Sr)' 
_chemical_formula_sum              
'As Cr Fe O3 Sr2'

_chemical_formula_weight 406.001

_exptl_crystal_F_000               ?
_exptl_crystal_density_diffrn      5.582(1)
_exptl_crystal_density_meas        ?
_exptl_crystal_density_method      ?

_cell_special_details
; 
none
;

_exptl_absorpt_coefficient_mu     76.587 
_exptl_absorpt_correction_type    none 
_exptl_absorpt_process_details    ?

_pd_meas_number_of_points              9600
_pd_proc_number_of_points              9600

_reflns_number_total                   108
_reflns_limit_h_min                    0
_reflns_limit_h_max                    3
_reflns_limit_k_min                    0
_reflns_limit_k_max                    3
_reflns_limit_l_min                    0
_reflns_limit_l_max                    15
_reflns_d_resolution_high              15.790
_reflns_d_resolution_low               1.003



###################
# 5. CRYSTAL DATA #
###################

# PLATON
loop_
_symmetry_equiv_pos_site_id         
_symmetry_equiv_pos_as_xyz          
   1 x,y,z                         
   2 1/2-y,x,z                     
   3 1/2-x,1/2-y,z                 
   4 y,1/2-x,z                     
   5 1/2+x,-y,-z                   
   6 1/2+y,1/2+x,-z                
   7 -x,1/2+y,-z                   
   8 -y,-x,-z                      
   9 -x,-y,-z                      
  10 1/2+y,-x,-z                   
  11 1/2+x,1/2+y,-z                
  12 -y,1/2+x,-z                   
  13 1/2-x,y,z                     
  14 1/2-y,1/2-x,z                 
  15 x,1/2-y,z                     
  16 y,x,z

_cell_length_a  3.91122(4)
_cell_length_b  3.91122(4)
_cell_length_c  15.79046(25)
_cell_angle_alpha 90
_cell_angle_beta  90
_cell_angle_gamma 90
_cell_volume 241.557(6)
_cell_formula_units_Z              2
_symmetry_cell_setting            'tetragonal' 
_symmetry_space_group_name_H-M    'P 4/n m m'
_symmetry_space_group_name_Hall   '-P 4a 2a'
_symmetry_Int_Tables_number        129

# PLATON
loop_
_atom_type_symbol                   
_atom_type_description              
_atom_type_scat_dispersion_real     
_atom_type_scat_dispersion_imag     
_atom_type_scat_source              
Sr  Sr   -0.3528    1.8200
 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
 O   O    0.0492    0.0322
 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
Fe  Fe   -1.1336    3.1974
 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
Cr  Cr   -0.1635    2.4439
 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
As  As   -0.9300    1.0051
 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_symmetry_multiplicity
_atom_site_Wyckoff_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_occupancy
Sr1 Sr 2 2c 0.75 0.75 0.19573(15) 0.0083(5) 1
Sr2 Sr 2 2c 0.75 0.75 0.41497(14) 0.0098(7) 1
Cr1 Cr 2 2c 0.25 0.25 0.31081(20) 0.0088(9) 1
Fe1 Fe 2 2a 0.25 0.75 0 0.0077(8) 1
As1 As 2 2c 0.25 0.25 0.08991(16) 0.0079(8) 1
O1 O 4 4f 0.25 0.75 0.29311(39) 0.0078(22) 1
O2 O 2 2c 0.25 0.25 0.43134(58) 0.0088(30) 1



#######################
# 6. BONDS AND ANGLES #
#######################

# PLATON
loop_
_geom_bond_atom_site_label_1        
_geom_bond_atom_site_label_2        
_geom_bond_distance                 
_geom_bond_site_symmetry_1          
_geom_bond_site_symmetry_2          
_geom_bond_publ_flag                
 Sr2     Cr1      3.2178(20)                     .       .                   yes
 As1     Fe1      2.4166(15)                     .     1_545                 yes
 As1     Fe1      2.4166(15)                     .     2_555                 yes
 As1     Fe1      2.4166(15)                     .       .                   yes
 As1     Fe1      2.4166(15)                     .     2_655                 yes
 Fe1     Fe1       2.7657(1)                     .     2_565                 yes
 Fe1     Fe1       2.7657(1)                     .     2_655                 yes
 Fe1     Fe1       2.7657(1)                     .     2_555                 yes
 Fe1     Fe1       2.7657(1)                     .     2_665                 yes
 Cr1     O1       1.9755(10)                     .       .                   yes
 Cr1     O2        1.903(10)                     .       .                   yes

loop_
_geom_angle_atom_site_label_1       
_geom_angle_atom_site_label_2       
_geom_angle_atom_site_label_3       
_geom_angle                         
_geom_angle_site_symmetry_1         
_geom_angle_site_symmetry_2         
_geom_angle_site_symmetry_3         
_geom_angle_publ_flag               
 Fe1     As1     Fe1        69.81(5)           1_545     .     2_655         yes
 Fe1     As1     Fe1      108.04(10)           2_555     .     2_655         yes
 Fe1     As1     Fe1        69.81(5)             .       .     2_655         yes
 Fe1     As1     Fe1      108.04(10)             .       .     1_545         yes
 Fe1     As1     Fe1        69.81(5)             .       .     2_555         yes
 Fe1     As1     Fe1        69.81(5)           1_545     .     2_555         yes
 As1     Fe1     Fe1        55.10(2)           5_565     .     2_655         yes
 Fe1     Fe1     Fe1           90.00           2_655     .     2_665         yes
 As1     Fe1     Fe1       124.91(2)           5_465     .     2_655         yes
 As1     Fe1     As1       108.04(7)             .       .     1_565         yes
 As1     Fe1     Fe1        55.10(2)             .       .     2_555         yes
 As1     Fe1     Fe1       124.91(2)             .       .     2_565         yes
 As1     Fe1     Fe1        55.10(2)             .       .     2_655         yes
 As1     Fe1     Fe1       124.91(2)             .       .     2_665         yes
 As1     Fe1     As1       110.19(3)             .       .     5_465         yes
 As1     Fe1     As1       110.19(3)             .       .     5_565         yes
 As1     Fe1     Fe1       124.91(2)           1_565     .     2_555         yes
 As1     Fe1     Fe1        55.10(2)           1_565     .     2_565         yes
 As1     Fe1     Fe1       124.91(2)           1_565     .     2_655         yes
 As1     Fe1     Fe1        55.10(2)           1_565     .     2_665         yes
 As1     Fe1     As1       110.19(3)           1_565     .     5_465         yes
 As1     Fe1     As1       110.19(3)           1_565     .     5_565         yes
 Fe1     Fe1     Fe1           90.00           2_555     .     2_565         yes
 Fe1     Fe1     Fe1           90.00           2_555     .     2_655         yes
 Fe1     Fe1     Fe1          180.00           2_555     .     2_665         yes
 As1     Fe1     Fe1        55.10(2)           5_465     .     2_555         yes
 As1     Fe1     Fe1       124.91(2)           5_565     .     2_555         yes
 Fe1     Fe1     Fe1          180.00           2_565     .     2_655         yes
 Fe1     Fe1     Fe1           90.00           2_565     .     2_665         yes
 As1     Fe1     Fe1        55.10(2)           5_465     .     2_565         yes
 As1     Fe1     Fe1       124.91(2)           5_565     .     2_565         yes
 As1     Fe1     Fe1       124.91(2)           5_465     .     2_665         yes
 As1     Fe1     Fe1        55.10(2)           5_565     .     2_665         yes
 As1     Fe1     As1       108.04(7)           5_465     .     5_565         yes
 Sr2     Cr1     O1        58.04(13)             .       .       .           yes
 Sr2     Cr1     O2         59.26(6)             .       .       .           yes
 O1      Cr1     O2        98.14(20)             .       .       .           yes


# start Validation Reply Form
_vrf_PUBL024_GLOBAL
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PROBLEM: The number of authors is greater than 5.
RESPONSE: Paper does not only contain crystallographic data. No submission to
Acta Crystallographica.
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#End of data_Sr2CrO3FeAs