Sample holder, electron microscope system and sample observation method
A sample holder enables easy control of a progress rate of a chemical reaction of a sample to be observed and facilitates observation of the chemical reaction. A sample holder includes a cylindrical holder outer cylinder, a sample holding section that is connected to one end of the holder outer cylinder and holds a sample, a gas reservoir tank that is connected to another end of the holder outer cylinder and stores gas, an orifice for ejecting the gas stored in the gas reservoir tank into the holder outer cylinder, and a valve for controlling a flow of the gas stored in the gas reservoir tank into the orifice. The sample holding section has an open end for discharging the gas supplied from the gas reservoir tank and having passed through the sample.
1 . A sample holder that holds a sample to be observed using an electron microscope, the sample holder comprising:
a cylindrical holder outer cylinder;
a sample holding section that is connected to one end of the holder outer cylinder and holds the sample;
a gas reservoir tank that is connected to another end of the holder outer cylinder and stores gas;
an orifice for ejecting the gas stored in the gas reservoir tank into the holder outer cylinder; and
a valve for controlling a flow of the gas stored in the gas reservoir tank into the orifice, wherein
the sample holding section has an open end for discharging the gas supplied from the gas reservoir tank and having passed through the sample.
2 . The sample holder according to claim 1 ,
wherein the valve is a piezoelectric driven valve.
3 . The sample holder according to claim 1 ,
wherein the valve is connected to the gas reservoir tank via a vibration-proof mechanism.
4 . The sample holder according to claim 1 ,
wherein the sample holding section includes a sample stage and an upper cover each having an electron beam passage hole, and
a MEMS chip is disposed above the electron beam passage hole of the sample stage, and
includes a membrane on which the sample is placed, and a silicon frame supporting the membrane.
5 . The sample holder according to claim 4 ,
wherein the MEMS chip further includes a metal heater on the membrane, and
at least a portion of a heater wiring through which a current is introduced into the metal heater is disposed in the holder outer cylinder.
6 . The sample holder according to claim 4 ,
wherein an electron beam permeable membrane that suppresses the discharge of the gas supplied from the gas reservoir tank through the electron beam passage hole of the upper cover is disposed on the electron beam passage hole of the upper cover.
7 . The sample holder according to claim 1 ,
wherein the sample holding section has, as the open end, an orifice row in which discharge orifices for discharging the gas supplied from the gas reservoir tank and having passed through the sample are arranged in a matrix.
8 . The sample holder according to claim 1 ,
wherein a cross-sectional area of the holder outer cylinder is 10 times or more a cross-sectional area of the orifice.
9 . An electron microscope system that includes an electron microscope having a column including an electron optical system, and in which the sample holder according to claim 1 is inserted from a side surface of the column,
the electron microscope system comprising:
a valve drive power source that controls opening and closing of the valve; and
a control computer that controls the valve drive power source, wherein
the control computer transmits a pulse control signal for controlling the opening degree of the valve to the valve drive power source to supply pulsed gas to the sample.
10 . The electron microscope system according to claim 9 , further comprising a source measure unit, wherein
a MEMS heating chip is disposed on the sample holding section of the sample holder,
the MEMS heating chip includes a membrane on which the sample is placed, a silicon frame supporting the membrane, and a metal heater disposed on the membrane, and
the source measure unit introduces a current into the metal heater via a heater wiring.
11 . The electron microscope system according to claim 10 ,
wherein the control computer controls the source measure unit to introduce the current into the metal heater synchronizing with the pulse control signal.
12 . The electron microscope system according to claim 9 , wherein
a discharge pipe for discharging gas from a sample chamber in which the sample holder is disposed,
the sample holding section of the sample holder has, as the open end, an orifice row in which discharge orifices for discharging gas supplied from the gas reservoir tank and having passed through the sample are arranged in a matrix, and
central axes of the discharge orifices pass through an opening of the discharge pipe.
13 . A sample observation method for observing a sample held in a sample holder using an electron microscope system, wherein
the sample holder includes a cylindrical holder outer cylinder, a sample holding section that is connected to one end of the holder outer cylinder and holds the sample, a gas reservoir tank that is connected to another end of the holder outer cylinder and stores gas, an orifice for ejecting the gas stored in the gas reservoir tank into the holder outer cylinder, and a valve for controlling a flow of the gas stored in the gas reservoir tank into the orifice, the sample holding section has an open end for discharging the gas supplied from the gas reservoir tank and having passed through the sample,
the electron microscope system includes an electron microscope including a column that includes an electron optical system and in which the sample holder is inserted from a side surface of the column, a valve drive power source, and a control computer that controls the valve drive power source,
the sample observation method comprising:
causing the control computer to transmit, to the valve drive power source, a pulse control signal for controlling an opening degree of the valve at a time of the observation of the sample; and
causing the valve drive power source to control the opening and closing of the valve to supply pulsed gas to the sample in response to the pulse control signal.
14 . The sample observation method according to claim 13 , wherein
after the control computer continuously transmits the pulse control signal to the valve drive power source a plurality of times, the control computer transmits a control signal of a base voltage to the valve drive power source,
the valve drive power source closes the valve in response to the control signal of the base voltage,
the electron microscope acquires an image of the sample a plurality of times in order to add the images during a period of time when the control computer transmits the control signal of the base voltage to the valve drive power source.
15 . The sample observation method according to claim 13 , wherein
a MEMS heating chip is disposed on the sample holding section of the sample holder,
the MEMS heating chip includes a membrane on which the sample is placed, a silicon frame supporting the membrane, and a metal heater disposed on the membrane,
the electron microscope system includes a source measure unit that introduces a current into the metal heater via a heater wiring, and
the control computer controls the source measure unit to introduce the current into the metal heater synchronizing with the pulse control signal.
16 . The sample observation method according to claim 14 , wherein
a MEMS heating chip is disposed on the sample holding section of the sample holder,
the MEMS heating chip includes a membrane on which the sample is placed, a silicon frame supporting the membrane, and a metal heater disposed on the membrane,
the electron microscope system includes a source measure unit that introduces a current into the metal heater via a heater wiring, and
the control computer controls the source measure unit to introduce the current into the metal heater synchronizing with the pulse control signal.