[et_pb_section fb_built=”1″ _builder_version=”4.16″ _module_preset=”default” background_color=”rgba(0,0,0,0.05)” custom_margin=”0px|0px|0px|0px|false|false” custom_padding=”0px|0px|0px|0px|false|false” global_colors_info=”{}”][et_pb_row column_structure=”1_2,1_2″ _builder_version=”4.16″ _module_preset=”default” custom_margin=”0px||0px||true|false” custom_padding=”11px||3px||false|false” global_colors_info=”{}”][et_pb_column type=”1_2″ _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}”][et_pb_button button_url=”@ET-DC@eyJkeW5hbWljIjp0cnVlLCJjb250ZW50IjoicG9zdF9saW5rX3VybF9wYWdlIiwic2V0dGluZ3MiOnsicG9zdF9pZCI6IjQ0MzkifX0=@” button_text=”Back to all projects” _builder_version=”4.22.1″ _dynamic_attributes=”button_url” _module_preset=”default” custom_button=”on” button_text_color=”#225500″ button_border_width=”0px” button_icon=”J||divi||400″ locked=”off” global_colors_info=”{}”][\/et_pb_button][\/et_pb_column][et_pb_column type=”1_2″ _builder_version=”4.17.0″ _module_preset=”default” global_colors_info=”{}”][et_pb_button button_url=”@ET-DC@eyJkeW5hbWljIjp0cnVlLCJjb250ZW50IjoicG9zdF9saW5rX3VybF9wYWdlIiwic2V0dGluZ3MiOnsicG9zdF9pZCI6IjU1MTcifX0=@” button_text=”Surface Physics Research Equipment” _builder_version=”4.27.4″ _dynamic_attributes=”button_url” _module_preset=”default” custom_button=”on” button_text_color=”#225500″ button_border_width=”0px” button_icon=”J||divi||400″ global_colors_info=”{}”][\/et_pb_button][\/et_pb_column][\/et_pb_row][\/et_pb_section][et_pb_section fb_built=”1″ _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}”][et_pb_row _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n
<\/span><\/p>\n <\/span><\/p>\n [\/et_pb_text][et_pb_divider color=”#215500″ divider_weight=”2px” _builder_version=”4.16″ _module_preset=”default” custom_margin=”-23px||6px||false|false” global_colors_info=”{}”][\/et_pb_divider][et_pb_text _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n Determining the equilibrium concentration of defects at high temperatures is essential in studying innovative materials’ physical and chemical properties, e.g., materials for gas sensors, heterogenous catalysis, high-temperature fuel cells, resistive switched memories, piezoelectric\/ferroelectric oxides, etc. For such analysis of the type of defect, their concentration and activation energy can be determined using different physical and chemical techniques.<\/p>\n The most popular method of defect chemistry is based on measuring the electrical conductivity as a function of the partial pressure of different oxidizing and reducing gases. Although such investigations are essential and have a long tradition, a crucial point is controlling the gas partial pressure, such as the oxygen partial pressure. The pressure can be adjusted by conventional gas mixing (buffer gases, like CO\/CO2 or H2\/H2O) or electrochemically using the oxygen pump (YSZ).<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row column_structure=”1_2,1_2″ _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”1_2″ _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}”][et_pb_image src=”https:\/\/measline.com\/wp-content\/uploads\/2025\/05\/Urzadzenie-do-analizy-defektow-2.jpg” alt=”Defect Analysis Device” title_text=”Defect Analysis Device” _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][\/et_pb_image][et_pb_image src=”https:\/\/measline.com\/wp-content\/uploads\/2025\/06\/Schemat-pomiarowy-probek-w-ukladzie-czteroelektrodowym-1.jpg” alt=”Sample Measurement Scheme in a Four-Electrode System” title_text=”Sample Measurement Scheme in a Four-Electrode System” _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][\/et_pb_image][\/et_pb_column][et_pb_column type=”1_2″ _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.27.4″ _module_preset=”default” custom_padding=”2px||0px|||” global_colors_info=”{}”]<\/p>\n \n This new method for controlling partial pressure connected the possibility of generating the XHV or \u00a0UHV conditions and the precise introduction of the defined doses of various gases in the vacuum system. Additionally, in our apparatus, the partial pressure of the gases is not dependent on the temperature of the mixing gases or the temperature of the oxygen pump, which needs sufficient ionic conductivity; therefore, the YSZ pump or sensor cannot be used below 500 \u00b0C.<\/p>\n <\/span><\/p>\n The advantage of this technique is the ability to include, in the interpretation of data from electrical conductivity measurements (obtained in 4-point geometry), direct information about the physical and chemical properties of the surface, which are essential for the analysis of the mechanism of exchange between the gas and surface interior. This comparison doesn\u2019t directly offer the chemical and electrochemical methods. Using surface-sensitive methods for the study of stoichiometry, electronic structure (using XPS, synchrotron radiation, EELS), crystallography, defect distribution (LEED, STM, AFM), and measurement of local electrical conductivity (with atomic resolution-LCAFM) of the surface layer can broaden the field of analysis while interpreting data from macroscopic conductivity measurements only.\u00a0<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row column_structure=”1_2,1_2″ _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”1_2″ _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n Tests carried out for model oxides (here, the single SrTiO3 crystal) have shown perfect conformity between Brouwer\u2019s diagram and the point defect diagram, which has been determined based on classical control of the partial pressure.<\/p>\n <\/p>\n [\/et_pb_text][et_pb_text _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n Brouwer diagrams of model materials for defect chemistry (here SrTiO3 single crystal) determined with the apparatus for 2-point and (b) 4-point geometry.<\/span><\/em><\/p>\n [\/et_pb_text][\/et_pb_column][et_pb_column type=”1_2″ _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_image src=”https:\/\/measline.com\/wp-content\/uploads\/2025\/05\/Diagramy-Brouwera-w-chemii-defektow.jpg” alt=”Brouwer diagrams of model materials for defect chemistry ” title_text=”Brouwer diagrams of model materials for defect chemistry ” _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][\/et_pb_image][\/et_pb_column][\/et_pb_row][\/et_pb_section][et_pb_section fb_built=”1″ _builder_version=”4.16″ _module_preset=”default” background_color=”rgba(0,0,0,0.05)” custom_padding=”37px|||||” global_colors_info=”{}”][et_pb_row admin_label=”Wiersz” _builder_version=”4.16.0″ _module_preset=”default” custom_padding=”||0px|||” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.27.4″ _module_preset=”default” min_height=”305px” custom_margin=”-12px||||false|false” custom_padding=”0px||3px||false|false” global_colors_info=”{}”]<\/p>\n <\/span><\/p>\n<\/div>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][\/et_pb_section][et_pb_section fb_built=”1″ _builder_version=”4.16″ _module_preset=”default” custom_padding=”30px||||false|false” global_colors_info=”{}”][et_pb_row _builder_version=”4.16″ _module_preset=”default” custom_padding=”0px||0px||false|false” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n DC 4-point method (with triaxial shielding of the electrical connections)<\/span><\/strong><\/p>\n<\/td>\n<\/tr>\n Temperature<\/span><\/p>\n<\/td>\n RT-1100\u00b0C (\u00b10.05\u00b0C )<\/span><\/p>\n<\/td>\n<\/tr>\n p<5\u00d710<\/span>-10 <\/span><\/span><\/span><\/sup>mbar (UHV)<\/span><\/p>\n p<1\u00d710\u203e\u00b9\u00b2<\/span><\/span>\u00a0<\/span><\/span><\/span><\/sup>mbar (XHV)<\/span><\/p>\n<\/td>\n<\/tr>\n from 10\u203e\u2079<\/span><\/span> to 10\u00b3<\/span><\/span>mbar\u00a0 – dynamically <\/span><\/p>\n from the pressure higher than 10\u203e\u00b3<\/span><\/span>–<\/span><\/span><\/span>10\u00b3<\/span><\/span>\u00a0-statically<\/span><\/p>\n<\/td>\n<\/tr>\n Determination of gas pressure calibrated vacuum gauge optional: the partial pressure of different gases measured using a mass spectrometer <\/p>\n<\/td>\n<\/tr>\n The resistance of the sample <\/span><\/p>\n<\/td>\n should not be higher than 10\u00b9\u00b2<\/span><\/span>\u00a0Ohm<\/span><\/p>\n<\/td>\n<\/tr>\n Measurement modes<\/span><\/span><\/p>\n<\/td>\n I-const. I (100mA- 1fA), Vvar.( \u00b1 200V, adjustable compliance) <\/span><\/p>\n V-const. V<\/span>max<\/span> (\u00b1 200V), I (100mA- 100fA, adjustable compliance),<\/span><\/p>\n<\/td>\n<\/tr>\n Type of samples<\/span><\/span><\/p>\n<\/td>\n single crystal, ceramic, powder, thin films <\/span><\/p>\n max. dimension 1\u00d70.5\u00d70.3 cm\u00b3<\/span><\/span><\/p>\n<\/td>\n<\/tr>\n \u00a0<\/span><\/p>\n<\/td>\n \u00a0<\/span><\/p>\n<\/td>\n<\/tr>\n Method<\/span><\/p>\n<\/td>\n AC 4-point methods with lock-in technique ( f =1Hz- 1kHz)<\/span><\/strong><\/span><\/p>\n<\/td>\n<\/tr>\n Temperature<\/span><\/p>\n<\/td>\n RT-1100\u00b0C (\u00b10.05\u00b0C)<\/span><\/span><\/strong><\/p>\n<\/td>\n<\/tr>\n The resistance of the sample<\/span><\/p>\n<\/td>\n should not be higher than 10\u2079<\/span><\/span>\u00a0Ohm<\/span><\/span><\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=”4.16″ _module_preset=”default” locked=”off” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][\/et_pb_text][et_pb_text _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n We invite you to explore the publication presenting the results achieved with the device described above: Ch. Rodenbucher et al. <\/span>APL Mater. 9, 011106 (2021)<\/span><\/strong><\/p>\n Explore other system configurations that offer extended functionality and broader application possibilities:<\/p>\nat high temperatures and various activities of gasses, based on the physical method for controlling the partial pressure of different gasses<\/span><\/h3>\n
Conductivity measurements under controlled partial pressures for investigating defect chemistry<\/h3>\n
The most significant device features:<\/span><\/span><\/h3>\n
\n
\u2013 Partial pressure control is not dependent on the temperature of gas mixtures or the operation of oxygen pumps
\u2013 Eliminates the need for YSZ oxygen pumps, which require ionic conductivity and cannot operate below 500\u202f\u00b0C
\u2013 Allows experiments at lower temperatures inaccessible to traditional electrochemical control systems<\/li>\n
\u2013 Enables operation under XHV (extremely high vacuum) or UHV (ultra-high vacuum) conditions
\u2013 Allows accurate introduction of well-defined doses of various gases into the vacuum system<\/li>\n
Enables simultaneous analysis of electrical conductivity (e.g. using 4-point probe geometry) and direct information on surface stoichiometry, electronic structure, defect distribution, local surface conductivity<\/li>\n<\/ul>\n<\/div>\nSpecification:<\/h3>\n
\n\n
\n Method<\/td>\n \n \n \n \n \n Basis vacuum<\/span><\/td>\n \n \n Gas Pressure Adjustment<\/td>\n \n \n \n
<\/span> (e.g., O\u2082<\/span>, N\u2082<\/span>, Ar, H\u2082<\/span><\/span>) <\/span><\/p>\n<\/td>\n\n
<\/span> (resolution 1% per decade to 10\u203e\u2074\u00a0<\/span><\/span>mbar, 0.01% per decade above 10\u203e\u2074\u00a0<\/span><\/span>mbar), <\/span><\/p>\n
(10\u203e\u2074\u00a0<\/span><\/span>mbar direct, above 10\u203e\u2074\u00a0<\/span><\/span>mbar with additional differential pumping stage)<\/span><\/p>\n\n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n