diff --git a/src/nomad_measurements/utils.py b/src/nomad_measurements/utils.py
index 2805174..766eaa1 100644
--- a/src/nomad_measurements/utils.py
+++ b/src/nomad_measurements/utils.py
@@ -226,8 +226,8 @@ def add_dataset(
     ):
         """
         Add a dataset to the HDF5 file. The dataset is written lazily (default) when
-        either `read_dataset` or `write_file` method is called. The `path` is validated
-        against the `valid_dataset_paths` if provided before adding the data.
+        `write_file` method is called. The `path` is validated against the
+        `valid_dataset_paths` if provided before adding the data.
 
         `params` should be a dictionary containing `data`. Optionally,
         it can also contain `archive_path` and `internal_reference`:
@@ -278,8 +278,7 @@ def add_attribute(
     ):
         """
         Add an attribute to the dataset or group at the given path. The attribute is
-        written lazily (default) when either `read_dataset` or `write_file` method is
-        called.
+        written lazily (default) when `write_file` method is called.
 
         Args:
             path (str): The dataset or group path in the HDF5 file.
@@ -297,19 +296,27 @@ def add_attribute(
     def read_dataset(self, path: str):
         """
         Returns the dataset at the given path. If the quantity has `units` as an
-        attribute, tries to returns a `pint.Quantity`. Before returning the dataset, the
-        method also writes the file with any pending datasets.
+        attribute, tries to returns a `pint.Quantity`.
+        If the dataset available in the `self._hdf5_datasets`, it is returned directly.
 
         Args:
             path (str): The dataset path in the HDF5 file.
         """
-        if self._hdf5_datasets or self._hdf5_attributes:
-            self.write_file()
         if path is None:
             return
         file_path, dataset_path = path.split('#')
-        file_name = file_path.rsplit('/raw/', 1)[1]
+
+        # find path in the instance variables
         value = None
+        if dataset_path in self._hdf5_datasets:
+            value = self._hdf5_datasets[dataset_path].data
+            if dataset_path in self._hdf5_attributes:
+                units = self._hdf5_attributes[dataset_path].get('units', None)
+                if units:
+                    value *= ureg(units)
+            return value
+
+        file_name = file_path.rsplit('/raw/', 1)[1]
         with h5py.File(self.archive.m_context.raw_file(file_name, 'rb')) as h5:
             if dataset_path not in h5:
                 self.logger.warning(f'Dataset "{dataset_path}" not found.')
diff --git a/src/nomad_measurements/xrd/schema.py b/src/nomad_measurements/xrd/schema.py
index f98278b..b1b0ffe 100644
--- a/src/nomad_measurements/xrd/schema.py
+++ b/src/nomad_measurements/xrd/schema.py
@@ -318,7 +318,14 @@ def normalize(self, archive, logger):
             ),
             validate_path=False,
         )
-
+        hdf5_handler.add_attribute(
+            path=f'{prefix}/plot_intensity',
+            params=dict(
+                axes='two_theta',
+                signal='intensity',
+                NX_class='NXdata',
+            ),
+        )
         for var_axis in ['omega', 'phi', 'chi']:
             if self.get(var_axis) is not None:
                 hdf5_handler.add_dataset(
@@ -338,16 +345,9 @@ def normalize(self, archive, logger):
                         NX_class='NXdata',
                     ),
                 )
-                return
+                break
 
-        hdf5_handler.add_attribute(
-            path=f'{prefix}/plot_intensity',
-            params=dict(
-                axes='two_theta',
-                signal='intensity',
-                NX_class='NXdata',
-            ),
-        )
+        hdf5_handler.write_file()
 
 
 class XRDResultPlotIntensityScatteringVector(ArchiveSection):
@@ -465,6 +465,7 @@ def normalize(self, archive, logger):
                     NX_class='NXdata',
                 ),
             )
+        hdf5_handler.write_file()
 
 
 class XRDResult(MeasurementResult):